PRUDENTIAL SERIES FUND INC, 497, 2000-01-07

PRUDENTIAL SERIES FUND INC
497, 2000-01-07

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THE PRUDENTIAL SERIES FUND, INC.
PRUDENTIAL JENNISON PORTFOLIO

20/20 FOCUS PORTFOLIO

PROSPECTUS: May 1, 1999

As with all mutual funds, filing this prospectus with the SEC does not mean
that the SEC has judged this Fund a good investment, nor has the SEC
determined that this prospectus is complete or accurate. It is a criminal
offense to state otherwise.

[LOGO] PRUDENTIAL
INVESTMENTS

<PAGE>

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TABLE OF CONTENTS

1 RISK/RETURN SUMMARY

Prudential Jennison Portfolio
-----------------------------
1 Investment Objective and Principal Strategies
1 Principal Risks
2 Evaluating Performance

20/20 Focus Portfolio
---------------------
3 Investment Objective and Principal Strategies
3 Principal Risks
3 Evaluating Performance

4 HOW THE PORTFOLIOS INVEST
4 Prudential Jennison Portfolio
6 20/20 Focus Portfolio

8 INVESTMENT RISKS

12 HOW THE PORTFOLIOS ARE MANAGED
12 Investment Adviser
12 Investment Sub-Advisers
12 Portfolio Managers

13 HOW TO BUY AND SELL SHARES OF THE FUND
13 How to Buy and Sell Shares
13 Net Asset Value
14 Distributor

14 OTHER INFORMATION
14 Federal Income Taxes
15 Year 2000
15 Monitoring for Possible Conflicts

16 FINANCIAL HIGHLIGHTS

For More Information (Back Cover)

<PAGE>

RISK/RETURN SUMMARY

This prospectus provides information about the Jennison Portfolio and the 20/20
Focus Portfolio (each, a Portfolio, and collectively, the Portfolios), which are
separate portfolios of the Prudential Series Fund, Inc. (the Fund).

The Fund offers two classes of shares in each Portfolio: Class I and Class II.
This prospectus relates only to Class II shares of the Portfolios. Class II
shares are sold only to separate accounts of insurance companies other than The
Prudential Insurance Company of America (Prudential) as investment options under
variable life insurance and variable annuity contracts (the Contracts). (A
separate account is simply an accounting device used to keep the assets invested
in certain insurance contracts separate from the general assets and liabilities
of the insurance company.)

The following section highlights key information about each Portfolio.
Additional information follows this summary and is provided in the Fund's
Statement of Additional Information (SAI), which provides information with
respect to all of the investment portfolios of the Fund, including the Jennison
Portfolio and the 20/20 Focus Portfolio.

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PRUDENTIAL JENNISON PORTFOLIO
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INVESTMENT OBJECTIVE AND PRINCIPAL STRATEGIES

Our investment objective is to achieve LONG-TERM GROWTH OF CAPITAL. To achieve
our objective, we invest primarily in equity securities of major established
corporations that we believe offer above-average growth prospects. In addition,
the Portfolio may invest up to 30% of its total assets in foreign securities.
While we make every effort to achieve our objective, we can't guarantee success.

PRINCIPAL RISKS

Although we try to invest wisely, all investments involve risk. Equity
securities - such as common stocks - are subject to COMPANY RISK. The price of
the stock of a particular company can vary based on a variety of factors, such
as the company's financial performance, changes in management and product
trends, and the potential for takeover and acquisition. Common stocks are also
subject to MARKET RISK stemming from factors independent of any particular
security. Investment markets fluctuate. All markets go through cycles and market
risk involves being on the wrong side of a cycle. Factors affecting market risk
include political events, broad economic and social changes, and the mood of the
investing public. You can see market risk in action during large drops in the
stock market. If investor sentiments turn gloomy, the price of all stocks may
decline. It may not matter that a particular company has great profits and its
stock is selling at a relatively low price. If the overall market is dropping,
the values of all stocks are likely to drop.

The Portfolio's investment in foreign securities involves additional risks. For
example, foreign banks and companies generally are not subject to the same types
of regulatory requirements that U.S. banks and companies are. Foreign political
developments and changes in currency rates may adversely affect the value of
foreign securities.

There is also risk involved in the investment strategies we may use. Some of our
strategies require us to try to predict whether the price or value of an
underlying investment will go up or down over a certain period of time. There is
always the risk that investments will not perform as we thought they would. Like
any mutual fund, an investment in the Portfolio could lose value, and you could
lose money. For more information about risk, see "Investment Risks."

1
<PAGE>

EVALUATING PERFORMANCE

A number of factors - including risk - affect how the Portfolio performs. The
following bar chart and table show the Portfolio's performance for each full
calendar year of operation for the last 3 years. They demonstrate the risk of
investing in the Portfolio and how returns can change from year to year. Past
performance does not mean that the Portfolio will achieve similar results in the
future.

Annual Returns* (Class I shares)
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1996 1997 1998
- ---------------------------------------------------------------------------
14.41% 31.71% 37.46%

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Best Quarter: 29.46% (4th quarter of 1998) Worst Quarter: (12.07)% (3rd
quarter of 1998)

* THESE ANNUAL RETURNS DO NOT INCLUDE CONTRACT CHARGES. IF CONTRACT CHARGES
WERE INCLUDED, THE ANNUAL RETURNS WOULD BE LOWER THAN THOSE SHOWN. SEE THE
ACCOMPANYING CONTRACT PROSPECTUS.

Average Annual Returns* (as of 12/31/98)
- ------------------------------------------------------------------------------
SINCE
INCEPTION
1 YEAR (4/25/95)
------ ---------
Class I shares 37.46% 29.60%
S&P 500** 28.60% 29.32%
Lipper Average*** 24.94% 25.38%

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* THE PORTFOLIO'S RETURNS ARE AFTER DEDUCTION OF EXPENSES AND DO NOT INCLUDE
CONTRACT CHARGES.

** THE STANDARD & POOR'S 500 STOCK INDEX (S&P 500) - AN UNMANAGED INDEX OF 500
STOCKS OF LARGE U.S. COMPANIES -GIVES A BROAD LOOK AT HOW STOCK PRICES HAVE
PERFORMED. THESE RETURNS DO NOT INCLUDE THE EFFECT OF ANY INVESTMENT
MANAGEMENT EXPENSES. THESE RETURNS WOULD BE LOWER IF THEY INCLUDED THE
EFFECT OF THESE EXPENSES. THE "SINCE INCEPTION" RETURN REFLECTS THE CLOSEST
CALENDAR MONTH-END RETURN (4/30/95). SOURCE: LIPPER, INC.

*** THE LIPPER VARIABLE INSURANCE PRODUCTS (VIP) GROWTH AVERAGE IS CALCULATED
BY LIPPER ANALYTICAL SERVICES, INC. AND REFLECTS THE INVESTMENT RETURN OF
CERTAIN PORTFOLIOS UNDERLYING VARIABLE LIFE AND ANNUITY PRODUCTS. THE
RETURNS ARE NET OF INVESTMENT FEES AND FUND EXPENSES BUT NOT PRODUCT
CHARGES. THE "SINCE INCEPTION" RETURN REFLECTS THE CLOSEST CALENDAR
MONTH-END RETURN (4/30/95). SOURCE: LIPPER, INC.

<PAGE>

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20/20 FOCUS PORTFOLIO
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INVESTMENT OBJECTIVE AND PRINCIPAL STRATEGIES

Our investment objective is LONG-TERM GROWTH OF CAPITAL. We seek to achieve this
goal by investing primarily in up to 40 equity securities of U.S. companies that
are selected by the Portfolio's two portfolio managers (up to 20 by each) as
having strong capital appreciation potential. One manager will use a "value"
approach which means he will attempt to identify strong companies selling at a
discount from their perceived true value. The other manager will use a "growth"
approach, which means he seeks companies that exhibit higher-than-average
earnings growth. Up to 20% of the Portfolio's total assets may be invested in
foreign securities. While we make every effort to achieve our objective, we
can't guarantee success.

PRINCIPAL RISKS

Because our strategy for the Portfolio involves investing primarily in 40 or
fewer securities, there is the risk that a loss resulting from the decline in
value of one security may represent a greater portion of the total assets of the
Portfolio than a portfolio that invests in a greater number of securities. In
addition, the Portfolio's investments may not be as widely spread across sectors
of the economy as a portfolio with a greater number of securities. Thus, the
Portfolio's performance may be more sensitive to developments in a single sector
of the economy than other portfolios.

EVALUATING PERFORMANCE

The Portfolio commenced operations in 1999, so there is no performance history
to report.

<PAGE>

HOW THE PORTFOLIOS INVEST

While the Portfolios have some common attributes, each one has its own portfolio
managers, investment objective and policies, performance information, and risks.
Therefore, some sections of this prospectus deal with each Portfolio separately,
while other sections address two or more Portfolios at the same time. In
sections that concern one particular Portfolio as identified in the section
heading, "the Portfolio" refers to that particular Portfolio.

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PRUDENTIAL JENNISON PORTFOLIO
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INVESTMENT OBJECTIVE AND POLICIES

The investment objective of this Portfolio is to achieve LONG TERM GROWTH OF
CAPITAL. This means we seek investments whose price will increase over several
years. While we make every effort to achieve this objective, we can't guarantee
success.

- -----------SIDEBAR-----------------------------------------------------
INVESTMENT STRATEGY

We seek to invest in equity securities of established
companies with above-average growth prospects. We select
stocks on a company-by-company basis using fundamental
analysis. In making our stock picks, we look for companies
that have had growth in earnings and sales, high returns on
equity and assets or other strong financial characteristics.
Often, the companies we choose have superior management, a
unique market niche or a strong new product.

- -----------------------------------------------------------------------

In pursuing our objective, we normally invest 65% of the Portfolio's total
assets in common stocks and preferred stocks of companies with capitalization in
excess of $1 billion.

For the balance of the Portfolio, we may invest in COMMON STOCKS, PREFERRED
STOCKS and OTHER EQUITY-RELATED SECURITIES of companies that are undergoing
changes in management, product and/or marketing dynamics which we believe have
not yet been reflected in reported earnings or recognized by investors.

In addition, we may invest in DEBT SECURITIES and MORTGAGE-RELATED SECURITIES.
These securities may be rated as low as Baa by Moody's or BBB by S&P (or if
unrated, of comparable quality in our judgment).

The Portfolio may also invest in OBLIGATIONS ISSUED OR GUARANTEED BY THE U.S.
GOVERNMENT, ITS AGENCIES AND INSTRUMENTALITIES. In addition, up to 30% of the
Portfolio's assets may be invested in FOREIGN EQUITY and EQUITY-RELATED
SECURITIES. For these purposes, we do not consider American Depositary Receipts
(ADRs) as foreign securities. (ADRs are certificates representing the right to
receive foreign securities that have been deposited with a U.S. bank or a
foreign branch of a U.S. bank.)

In response to adverse market conditions or when restructuring the Portfolio, we
may invest up to 100% of the Portfolio's assets in MONEY MARKET instruments.
Investing heavily in these securities limits our ability to achieve our
investment objective, but can help to preserve the Portfolio's assets when the
markets are unstable.

DERIVATIVES AND OTHER STRATEGIES

We may also use alternative investment strategies - including DERIVATIVES to try
to improve the Portfolio's returns, protect its assets or for short-term cash
management. There is no guarantee that these strategies will work, that the
instruments necessary to implement these strategies will be available or that
the Portfolio will not lose money. With derivatives, we try to predict whether
the underlying investment - a security, market index, currency or some other
benchmark - will go up or down at some future date. We may use derivatives to
try to reduce risk or to increase return consistent with the Portfolio's overall
investment objective.

<PAGE>

We may: purchase and sell OPTIONS on equity securities, stock indexes and
foreign currencies; purchase and sell stock index and foreign currency FUTURES
CONTRACTS and options on those futures contracts; enter into FORWARD FOREIGN
CURRENCY EXCHANGE CONTRACTS; and purchase securities on a WHEN-ISSUED or DELAYED
DELIVERY basis.

The Portfolio may also enter into SHORT SALES AGAINST-THE-BOX. In a short sale
we sell a security we do not own to take advantage of an anticipated decline in
the stock's price. The Portfolio borrows the stock for delivery and if it can
buy the stock later at a lower price, a profit results. A short sale is
"against-the-box" when the Portfolio owns an equal amount of the securities sold
short or owns securities that can be converted into the securities sold.

The Portfolio may also enter into REPURCHASE AGREEMENTS. In a repurchase
transaction, the Portfolio agrees to purchase certain securities and the seller
agrees to repurchase the same securities at a set price on a specified date.
This creates a fixed return for the Portfolio. The Portfolio may participate
with certain other Portfolios of the Fund in a JOINT REPURCHASE ACCOUNT under an
order obtained from the SEC. In a joint repurchase transaction, uninvested cash
balances of various Portfolios are added together and invested in one or more
repurchase agreements. Each of the participating Portfolios receives a portion
of the income earned in the joint account based on the percentage of its
investment.

We will consider factors such as cost and volatility in deciding whether to
employ any particular strategy or use any particular instrument. Any derivatives
we use may not match the Portfolio's underlying holdings. For more information
about these strategies, see the SAI, "Investment Objectives and Policies of the
Portfolios."

ADDITIONAL STRATEGIES

The Portfolio also follows certain policies when it BORROWS money (the Portfolio
may borrow up to 5% of the value of its total assets); LENDS ITS SECURITIES; and
holds ILLIQUID SECURITIES (the Portfolio may hold up to 15% of its net assets in
illiquid securities, including securities with legal or contractual restrictions
on resale, those without a readily available market and repurchase agreements
with maturities longer than seven days). The Portfolio is subject to certain
investment restrictions that are fundamental policies, which means they cannot
be changed without shareholder approval. For more information about these
restrictions, see the SAI.

<PAGE>

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20/20 FOCUS PORTFOLIO
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INVESTMENT OBJECTIVE AND POLICIES

The investment objective of this Portfolio is LONG-TERM GROWTH OF CAPITAL. This
means we seek investments whose price will increase over several years. While we
make every effort to achieve this objective, we can't guarantee success.

- -----------SIDEBAR--------------------------------------------------------------
VALUE & GROWTH APPROACHES

Our strategy is to combine the efforts of two outstanding
portfolio managers, each with a different investment style,
and to invest in only the favorite stock picks of each
manager. One manager will invest using a VALUE approach,
which means he will attempt to identify strong companies
selling at a discount from their perceived true value. The
other manager will use a GROWTH approach, which means he
seeks companies that exhibit higher-than-average earnings
growth.
- -------------------------------------------------------------------------------

To achieve this objective, the Portfolio will invest primarily in up to 40
equity securities of U.S. companies that are selected by the Portfolio's two
portfolio managers as having strong capital appreciation potential. Each
portfolio manager will manage his own portion of the Portfolio's assets, which
will usually include a maximum of 20 securities. Because the Portfolio will be
investing in 40 or fewer securities, an investment in this Portfolio may be
riskier than an investment in a more widely diversified fund. We intend to be
fully invested, holding less than 5% in cash, under normal market conditions.

Normally, the Portfolio will invest at least 80% of its total assets in common
stocks and equity-related securities such as PREFERRED STOCKS, CONVERTIBLE
STOCKS, and equity interests in PARTNERSHIPS, JOINT VENTURES and OTHER
NONCORPORATE ENTITIES. We may also invest in WARRANTS and similar rights that
can be exercised for equity securities, but will not invest more than 5% of the
Portfolio's total assets in unattached warrants or rights. The Portfolio may
invest up to 20% of its total assets in CASH, OBLIGATIONS ISSUED OR GUARANTEED
BY THE U.S. GOVERNMENT, ITS AGENCIES AND INSTRUMENTALITIES and DERIVATIVES. Up
to 20% of the Portfolio's total assets may be invested in FOREIGN SECURITIES.
For these purposes, we do not consider American Depositary Receipts (ADRs) as
foreign securities. (ADRs are certificates representing the right to receive
foreign securities that have been deposited with a U.S. bank or a foreign branch
of a U.S. bank.)

The Portfolio may also invest in REAL ESTATE INVESTMENT TRUSTS (REITs). A REIT
is a company that manages a portfolio of real estate to earn profits for its
shareholders. Some REITs acquire equity interests in real estate and then
receive income from rents and capital gains when the buildings are sold. Other
REITs lend money to real estate developers and receive interest income from the
mortgages. Some REITs invest in both types of interests.

We may invest in high quality MONEY MARKET INSTRUMENTS. In response to adverse
market conditions or when restructuring the Portfolio, we may invest up to 100%
of the Portfolio's assets in money market instruments. Investing heavily in
these securities limits our ability to achieve our investment objective, but can
help to preserve the Portfolio's assets when the markets are unstable.

<PAGE>

DERIVATIVES AND OTHER STRATEGIES

We may also use alternative investment strategies - including DERIVATIVES to try
to improve the Portfolio's returns, protect its assets or for short-term cash
management. There is no guarantee that these strategies will work, that the
instruments necessary to implement these strategies will be available or that
the Portfolio will not lose money. With derivatives, we try to predict whether
the underlying investment - a market index, currency or some other benchmark -
will go up or down at some future date. We may use derivatives to try to reduce
risk or to increase return consistent with the Portfolio's overall investment
objective.

We may: purchase and sell OPTIONS on financial indexes that are traded on U.S or
foreign securities exchanges or in the over-the-counter market; purchase and
sell FUTURES CONTRACTS on stock indexes and foreign currencies and OPTIONS on
those contracts; and purchase or sell securities on a WHEN-ISSUED or DELAYED
DELIVERY basis.

The Portfolio may also enter into SHORT SALES. In a short sale we sell a
security we do not own to take advantage of an anticipated decline in the
stock's price. The Portfolio borrows the stock for delivery and if it can buy
the stock later at a lower price, a profit results. No more than 25% of the
Portfolio's net assets may be used as collateral or segregated for purposes of
securing a short sale obligation. We may also use up to 25% of the Portfolio's
net assets for SHORT SALES AGAINST-THE-BOX which means the Portfolio owns
securities identical to those sold short.

ADDITIONAL STRATEGIES

<PAGE>

INVESTMENT RISKS

AS NOTED, ALL INVESTMENTS INVOLVE RISK, AND INVESTING IN THE PORTFOLIOS IS NO
EXCEPTION. THIS CHART OUTLINES THE KEY RISKS AND POTENTIAL REWARDS OF THE
PRINCIPAL INVESTMENTS AND CERTAIN OTHER INVESTMENTS EACH PORTFOLIO MAY MAKE. SEE
ALSO, "INVESTMENT OBJECTIVES AND POLICIES OF THE PORTFOLIOS" IN THE SAI.

INVESTMENT PORTFOLIO &
TYPE % OF ASSETS RISKS POTENTIAL REWARDS
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<S> <C> <C> <C>
EQUITY AND Equity-related o Individual stocks could lose o Historically, stocks have
EQUITY-RELATED securities: value outperformed other
SECURITIES PRUDENTIAL JENNISON investments over the long
o The equity markets could go term
(AT LEAST 65%) down, resulting in a decline in
value of a Portfolio's investments o Generally, economic
growth means higher
20/20 FOCUS o Companies that pay dividends corporate profits, which
may not do so if they don't have leads to an increase in
(AT LEAST 80%) profits or adequate cash flow stock prices, known as
capital appreciation
o Changes in economic or
political conditions, both U.S. o May be a source of
and international, may result in dividend income
a decline in the value of a
Portfolio's investments o Highly successful
small-cap companies can
o Small-cap companies are more outperform larger ones
likely to reinvest earnings and
not pay dividends

o Changes in interest rates may affect
the securities of small- and
medium-sized companies more than the
securities of larger companies

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</TABLE>

<PAGE>

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<S> <C> <C> <C>
INVESTMENT PRUDENTIAL JENNISON o The Portfolio's holdings, o Bonds have generally
GRADE DEBT share price, yield, and total outperformed money market
SECURITIES (UP TO 35%) return may fluctuate in response instruments over the long
to bond market movements term with less risk than
stocks
o Credit risk - the default of
an issuer would leave a Portfolio o Most bonds will rise in
with unpaid interest or value when interest rates
principal. The lower a bond's fall
quality, the higher its potential
volatility o Regular interest income

o Market risk - the risk that o o Generally more secure risk
Investment grade bonds the market may affect an industry, than stocks
value of an investment have a lower since companies sector, or the
risk of default may move up or down, market as a whole must pay their
sometimes rapidly or unpredictably. debts before they pay dividends
Market

o Interest rate risk - the value of
most bonds will fall when interest
rates rise; the longer a bond's
maturity and the lower its credit
quality, the more its value
typically falls. It can lead to
price volatility
<CAPTION>
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<S> <C> <C> <C>
FOREIGN PRUDENTIAL JENNISON o Foreign markets, economies and o Investors can participate
SECURITIES political systems may not be as in the growth of foreign
(UP TO 35%) stable as in the U.S. markets and companies
operating in those markets
o Currency risk - changing
20/20 FOCUS values of foreign currencies o Changing value of foreign
currencies
(UP TO 20%) o May be less liquid than US
stocks and bonds o Opportunities for

o Differences in foreign laws, diversification
accounting standards, public
information, custody and
settlement practices

o Year 2000 conversion may be
more of a problem for some
foreign issuers

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</TABLE>

<PAGE>

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<S> <C> <C> <C>
DERIVATIVES Options on Equity o Derivatives, such as futures, o A Portfolio could make
Securities: PRUDENTIAL options and foreign currency money and protect against
JENNISON GROWTH forward contracts, may not fully losses if the investment
offset the underlying positions analysis proves correct
(% VARIES) and this could result in losses
to a Portfolio that would not o Derivatives that involve
Options on Stock Indexes: have otherwise occurred leverage could generate
BOTH PORTFOLIOS substantial gains at low cost
o Derivatives used for risk
(% VARIES) management may not have the o One way to manage a
intended effects and may result Portfolio's risk/return
Futures Contracts on in losses or missed opportunities balance is to lock in the
stock indexes: value of an investment ahead
BOTH PORTFOLIOS o The other party to a of time
derivatives contract could default
(% VARIES)
o Derivatives that involve
leverage could magnify losses

o Certain types of derivatives
involve costs to a Portfolio that
can reduce returns

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<CAPTION>
<S> <C> <C> <C>
MORTGAGE PRUDENTIAL JENNISON o Prepayment risk - the risk o Regular interest income
BACKED & that the underlying mortgage or
ASSET-BACKED (UP TO 35%) other debt may be prepaid o Pass-through instruments
SECURITIES partially or completely, provide greater
20/20 FOCUS generally during periods of diversification than direct
falling interest rates, which ownership of loans
(UP TO 20%) could adversely affect yield to
maturity and could require a o Certain mortgage-backed
Portfolio to reinvest in securities may benefit from
lower-yielding securities security interest in real

o Credit risk - the risk that estate
collateral the underlying mortgages
or receivables will not be paid by
debtors or by credit insurers or
guarantors of such instruments and
thus may involve greater risk
o Market risk
- ------------------------------------------------------------------------------- ---------------------------------
REAL ESTATE 20/20 FOCUS o Performance depends on the o Real estate holdings can
INVESTMENT strength of real estate markets, generate good returns from
TRUSTS (% VARIES) REIT management and property rents, rising market values,
(REITS) management which can be affected etc.
by many factors, including
national

- --------------------------------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>

and regional economic o Greater diversification
conditions than direct ownership
- ---------------------------------------------------------------------------------------------------------------------------
HIGH-QUALITY BOTH PORTFOLIOS o Credit risk-the risk that the o Regular interest income
MONEY MARKET borrower can't pay back the money
OBLIGATIONS (UP TO 100% ON A borrowed o Generally more secure
OF ALL TYPES TEMPORARY BASIS) than stocks since companies
o Market risk - the risk that must pay
their debts before the obligations
may lose value they pay dividends
because interest rates change or
there is a lack of confidence in the
borrower
- --------------------------------------------------------------------------------------------------------------------------
WHEN-ISSUED When-issued and delayed o Use of such instruments and o Use of instruments may
AND DELAYED delivery securities: strategies may magnify magnify underlying
DELIVERY PRUDENTIAL JENNISON underlying investment losses investment gains
SECURITIES
AND SHORT (% VARIES) o Investment costs may exceed
SALES potential underlying investment
Short Sales: gains
20/20 FOCUS

(% VARIES)

Short Sales Against the
Box:
BOTH PORTFOLIOS

(% VARIES)
- ------------------------------------------------------------------------------------------------------------------------
ILLIQUID BOTH PORTFOLIOS o May be difficult to value o May offer a more
SECURITIES precisely attractive yield than more
(15% OF NET ASSETS) widely traded securities
o May be difficult to sell at
the time or price desired
- ------------------------------------------------------------------------------------------------------------------------
</TABLE>

<PAGE>

HOW THE PORTFOLIOS ARE MANAGED

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INVESTMENT ADVISER
- ------------------------------------------------------------------------------

Prudential serves as the overall investment adviser for the Fund. Founded in
1875, it is responsible for the management of the Fund and provides investment
advice and related services to each Portfolio. As of December 31, 1998,
Prudential had total assets under management of approximately $334 billion.
Prudential is located at 751 Broad Street, Newark, New Jersey 07102-3777.

Prudential is currently considering reorganizing itself into a publicly traded
stock company through a process known as "demutualization." On February 10,
1998, the Company's Board of Directors authorized management to take the
preliminary steps necessary to allow the Company to demutualize. On July 1,
1998, legislation was enacted in New Jersey that would permit this conversion to
occur and that specified the process for conversion. Demutualization is a
complex process involving development of a plan of reorganization, adoption of a
plan by the Company's Board of Directors, a public hearing, voting by qualified
policyholders and regulatory approval, all of which could take two or more years
to complete. Prudential's management and Board of Directors have not yet
determined to demutualize and it is possible that, after careful review,
Prudential could decide not to go public.

The following chart lists the total investment advisory fees paid in 1998 as a
percentage of the Portfolio's average net assets. For the two new Portfolios,
the following chart describes the fee arrangement.

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TOTAL ADVISORY FEES AS %
PORTFOLIO OF AVERAGE NET ASSETS
------------------------------------------------------------
Prudential Jennison 0.60
20/20 Focus 0.75

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INVESTMENT SUB-ADVISERS
- ------------------------------------------------------------------------------

For each Portfolio, a sub-adviser provides day-to-day investment management.
Prudential pays the sub-adviser out of the fee Prudential receives from the
Fund.

Prudential Investment Corporation (PIC), a wholly owned subsidiary of
Prudential, provides investment advisory services for the value equity portion
of the 20/20 Focus Portfolio. PIC's address is 751 Broad Street, Newark, New
Jersey 07102.

Jennison Associates LLC (Jennison), a wholly owned subsidiary of Prudential,
provides substantially all of the investment advisory services for the
Prudential Jennison Portfolio and the growth equity portion of the assets for
the 20/20 Focus Portfolio. Jennison's address is 466 Lexington Avenue, New York,
New York 10017. As of December 31, 1998, Jennison had over $46 billion in assets
under management for institutional and mutual fund clients.

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PORTFOLIO MANAGERS
- ------------------------------------------------------------------------------

PRUDENTIAL JENNISON PORTFOLIO

This Portfolio is managed by Messrs. Spiros "Sig" Segalas, CFA, and James N.
Kannry, CFA, and Ms. Kathleen A. McCarragher, CFA, of Jennison since 1999.
Mr. Segalas is a founding member and President and Chief Investment Officer
of Jennison. He has been in the investment business for over 35 years. Mr.
Segalas is one of the co-managers of the Prudential Jennison Portfolio and
the 20/20 Focus Portfolio.

Mr. Kannry, a Director and Executive Vice President of Jennison, has been part
of the Jennison team since 1972. He spent more than a dozen years as part of
Jennison's research team before assuming portfolio management

<PAGE>

responsibilities several years ago. He holds a Chartered Financial Analyst
designation and is a member of the New York Society of Security Analysts.

Ms. McCarragher, Director and Executive Vice President of Jennison, is also
Jennison's Growth Equity Investment Strategist, having joined Jennison last year
after a 20 year investment career, including positions with Weiss, Peck & Greer
(1992-1998) and State Street Research and Management Company, where
she was a member of the Investment Committee.

20/20 FOCUS PORTFOLIO

Thomas R. Jackson, Managing Director of PIC, manages approximately 50% of the
Portfolio's assets. Mr. Jackson joined PIC in 1990 and has over 30 years of
professional equity investment management experience. He was formerly
co-chief investment officer of Red Oak Advisers and Century Capital
Associates, each a private money management firm, where he managed pension
and other accounts for institutions and individuals. Mr. Jackson was also
with The Dreyfus Corporation where he managed and served as president of the
Dreyfus Fund. Mr. Jackson began managing at Chase Manhattan Bank. He is a
member of the New York Society of Security Analysts.

Spiros Segalas, Director, President and Chief Investment Officer of Jennison,
manages approximately 50% of the Portfolio's assets. (See description under
"Jennison Portfolio," above.)

HOW TO BUY AND SELL SHARES OF THE PORTFOLIOS

The Fund offers two classes of shares in the Portfolio - Class I and Class II.
This prospectus relates only to Class II shares of the Portfolio. Class I shares
are sold only to separate accounts of Prudential as investment options under
certain Contracts. Class II is offered only to separate accounts of
non-Prudential insurance companies as investment options under certain of their
Contracts.

HOW TO BUY AND SELL SHARES

The only way to invest in the Portfolio is through certain variable life
insurance and variable annuity contracts. Together with this prospectus, you
should have received a prospectus for such a Contract. You should refer to that
prospectus for further information on investing in the Portfolio.

Class II shares of the Portfolio are sold without any sales charge at the net
asset value of the Portfolio. Class II shares, however, are subject to an annual
distribution or "12b-1" fee of 0.25% and an administration fee of 0.15% of the
average daily net assets of Class II. Class I shares do not have a distribution
or administration fee.

Shares are redeemed for cash within seven days of receipt of a proper notice of
redemption or sooner if required by law. There is no redemption charge. We may
suspend the right to redeem shares or receive payment when the New York Stock
Exchange is closed (other than weekends or holidays), when trading on the New
York Stock Exchange is restricted, or as permitted by the SEC.

NET ASSET VALUE

When you purchase or sell shares of the Portfolio the price you will pay or
receive, as the case may be, is based on the share's value. This is known as the
net asset value or NAV. The price at which a purchase or redemption is made is
based on the next calculation of the NAV after the order is placed. The NAV of
each share class of the Portfolio is determined once a day - at 4:15 p.m. New
York Time - on each day the New York Stock Exchange is open for business. If the
New York Stock Exchange closes early on a day, the Portfolio's NAV will be
calculated some time between the closing time and 4:15 p.m. on that day.

The NAV for the Portfolio is determined by a simple calculation. It's the total
value of the Portfolio (assets minus liabilities) divided by the total number of
shares outstanding.

<PAGE>

To determine the Portfolio's NAV, its holdings are valued as follows:

EQUITY SECURITIES are generally valued at the last sale price on an exchange or
NASDAQ, or if there is not sale, at the mean between the most recent bid and
asked prices on that day. If there is no asked price, the security will be
valued at the bid price. Equity securities that are not sold on an exchange or
NASDAQ are generally valued by an independent pricing agent or principal market
maker.

The Portfolio may own securities that are primarily listed on foreign exchanges
that trade on weekends or other days when the Portfolio does not price its
shares. Therefore, the value of the Portfolio's assets may change on days when
shareholders cannot purchase or redeem their shares.

All SHORT-TERM DEBT SECURITIES with remaining maturities of 60 days or less are
valued on an amortized cost basis. This valuation method is widely used by
mutual funds. It means that the security is valued initially at its purchase
price and then decreases in value by equal amounts each day until the security
matures. It almost always results in a value that is extremely close to the
actual market value. The Fund's Board of Directors has established procedures to
monitor whether any material deviation between valuation and market value occurs
and if so, will promptly consider what action, if any, should be taken to
prevent unfair results to Contract owners.

OTHER DEBT SECURITIES -- those that are not valued on an amortized cost basis --
are valued using an independent pricing service.

OPTIONS ON STOCK AND STOCK INDEXES that are traded on a national securities
exchange are valued at the average of the bid and asked prices as of the close
of that exchange.

FUTURES CONTRACTS and OPTIONS ON FUTURES CONTRACTS are valued at the last sale
price at the close of the commodities exchange or board of trade on which they
are traded. If there has been no sale that day, the securities will be valued at
the mean between the most recently quoted bid and asked prices on that exchange
or board of trade.

SECURITIES FOR WHICH NO MARKET QUOTATIONS ARE AVAILABLE will be valued at fair
value by Prudential under the direction of the Fund's Board of Directors.

DISTRIBUTOR

Prudential Investment Management Services LLC (PIMS) distributes the Fund's
shares under a Distribution Agreement with the Fund. The Fund has adopted a
distribution plan under Rule 12b-1 of the Investment Company Act of 1940
covering Class II shares. Under that plan, Class II of the Portfolio pay to PIMS
a distribution or "12b-1" fee at the annual rate of 0.25% of the average daily
net assets of Class II. This fee pays for distribution services for Class II
shares. Because these fees are paid out of the Portfolio's assets on an on-going
basis, over time these fees will increase the cost of your investment in Class
II shares and may cost you more than paying other types of sales charges.

OTHER INFORMATION

FEDERAL INCOME TAXES

If you own or are considering purchasing a variable contract, you should consult
the prospectus for the variable contract for tax information about that variable
contract. You should also consult with a qualified tax adviser for information
and advice.

The SAI provides information about certain tax laws applicable to the Fund.

<PAGE>

YEAR 2000

The services provided to the Fund and the shareholders by the Fund's investment
adviser, sub-advisers, distributor, transfer agent and custodians depend on the
smooth functioning of their computer systems and those of outside service
providers. Many computer software systems in use today cannot distinguish the
year 2000 from the year 1900 because of the way dates are encoded and
calculated. Such event could have a negative impact on handling securities
trades, payments of interest and dividends, pricing and account services.
Although, at this time, there can be no assurance that there will be no adverse
impact on the Fund, the Fund's investment adviser, sub-advisers, distributor,
transfer agent and custodians have advised the Fund that they have been actively
working on necessary changes to their computer systems to prepare for the year
2000. The Fund and its Directors receive and have received since mid-1998
satisfactory quarterly reports from the principal service providers as to their
preparations for year 2000 readiness, although there can be no assurance that
the service providers (or other securities market participants) will
successfully complete the necessary changes in a timely manner or that there
will be no adverse impact on the Fund. Moreover, the Fund at this time has not
considered retaining alternative service providers or directly undertaken
efforts to achieve year 2000 readiness, the latter of which would involve
substantial expenses without an assurance of success.

Additionally, issuers of securities generally as well as those purchased by the
Fund may confront year 2000 compliance issues which, if material and not
resolved, could have an adverse impact on securities markets and/or a specific
issuer's performance and result in a decline in the value of the securities held
by the Fund.

MONITORING FOR POSSIBLE CONFLICTS

The Fund sells its shares to fund variable life insurance contracts and variable
annuity contracts and may offer its shares to qualified retirement plans.
Because of differences in tax treatment and other considerations, it is possible
that the interest of variable life insurance contract owners, variable annuity
contract owners and participants in qualified retirement plans could conflict.
The Fund will monitor the situation and in the event that a material conflict
did develop, the Fund would determine what action, if any, to take in response.

<PAGE>

FINANCIAL HIGHLIGHTS

The financial highlights will help you evaluate the financial performance of
each Portfolio. The TOTAL RETURN in each chart represents the rate that a
shareholder earned on an investment in that share class of the Portfolio,
assuming reinvestment of all dividends and other distributions. The charts do
not reflect charges under any variable contract. The information is for Class I
for the periods indicated.

The information for the THREE YEARS ENDED DECEMBER 31, 1998 has been audited by
PRICEWATERHOUSECOOPERS LLP, whose unqualified report, along with the financial
statements, appear in the SAI, which is available upon request. THE INFORMATION
FOR THE PERIOD ENDED DECEMBER 31, 1995 WAS AUDITED BY THE OTHER INDEPENDENT
AUDITORS WHOSE REPORT WAS ALSO UNQUALIFIED.

PRUDENTIAL JENNISON
------------------------------------------------------------------------------
Year Ended
December 31, April 25, 1995(d)
------------------------------------------------ to
1998 1997 1996 December 31, 1995(a)
---- ---- ---- --------------------
<S> <C> <C> <C> <C>
PER SHARE OPERATING PERFORMANCE:
Net Asset Value, beginning of period ...... $17.73 $14.32 $12.55 $10.00
------ ------ ------ ------
INCOME FROM INVESTMENT OPERATIONS:
Net investment income ..................... 0.04 0.04 0.02 0.02
Net realized and unrealized gains on
investments ............................. 6.56 4.48 1.78 2.54
------ ------ ------ ------
Total from investment operations ...... 6.60 4.52 1.80 2.56
------ ------ ------ ------
LESS DISTRIBUTIONS:
Dividends from net investment income ...... (0.04) (0.04) (0.03) (0.01)
Distributions from net realized gains ..... (0.38) (1.07) -- --
------ ------ ------ ------
Total distributions ................... (0.42) (1.11) (0.03) (0.01)
------ ------ ------ ------
Net Asset Value, end of period ............ $23.91 $17.73 $14.32 $12.55
------ ------ ------ ------
TOTAL INVESTMENT RETURN:(b) ............... 37.46% 31.71% 41.41% 24.20
RATIOS/SUPPLEMENTAL DATA:
Net assets, end of period (in millions) ... $1,198.7 $495.9 $226.5 $63.1
Ratios to average net assets:
Expenses ................................ 0.63% 0.64% 0.66% 0.79%(c)
Net investment income ................... 0.20% 0.25% 0.20% 0.15%(c)
Portfolio turnover rate ................... 54% 60% 46% 37%
</TABLE>

(a) Calculations are based on average month-end shares outstanding.
(b) Total investment return is calculated assuming a purchase of shares on the
first day and a sale on the last day of each period reported and includes
reinvestment of dividends and distributions. Total investment returns for
less than a full year are not annualized.
(c) Annualized.
(d) Commencement of operations.

<PAGE>

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<PAGE>

FOR MORE INFORMATION

Additional information about the Fund and the Portfolio can be obtained upon
request without charge and can be found in the following documents:

STATEMENT OF ADDITIONAL INFORMATION (SAI)

(incorporated by reference into this prospectus)

ANNUAL REPORT

(including a discussion of market conditions and strategies that
significantly affected the Portfolio's performance during the previous year)

SEMI-ANNUAL REPORT

To obtain these documents or to ask any questions about the Fund:

- Call toll-free (800) 778-2255

- Write to The Prudential Series Fund, Inc., 751 BROAD STREET,
NEWARK, NJ 07102-3777

You can also obtain copies of Fund documents from the Securities and Exchange
Commission as follows:

By Mail:
- --------

Securities and Exchange Commission

Public Reference Section
Washington, DC 20549-6009
(The SEC charges a fee to copy documents.)

In Person:
- ----------

PUBLIC REFERENCE ROOM
IN WASHINGTON, DC
(For hours of operation, call 1(800) SEC-0330.)

Via the Internet:
- -----------------
http://www.sec.gov

SEC File No. 811-03623