<PAGE> PAGE 1
000 B000000 03/31/99
000 C000000 0000822337
000 D000000 N
000 E000000 NF
000 F000000 Y
000 G000000 N
000 H000000 N
000 I000000 3.0.a
000 J000000 A
001 A000000 PRUDENTIAL INSTITUTIONAL LIQUIDITY PORTFOLIO
001 B000000 811-5336
001 C000000 9733673028
002 A000000 GATEWAY CTR 3, 100 MULBERRY ST, 9TH FL.
002 B000000 NEWARK
002 C000000 NJ
002 D010000 07102
002 D020000 4077
003 000000 N
004 000000 N
005 000000 N
006 000000 N
007 A000000 N
007 B000000 0
007 C010100 1
007 C010200 2
007 C010300 3
007 C010400 4
007 C010500 5
007 C010600 6
007 C010700 7
007 C010800 8
007 C010900 9
007 C011000 10
008 A000001 PRUDENTIAL INVESTMENTS FUND MANAGEMENT LLC
008 B000001 A
008 C000001 801-31104
008 D010001 NEWARK
008 D020001 NJ
008 D030001 07102
008 D040001 4077
008 A000002 THE PRUDENTIAL INVESTMENT CORPORATION
008 B000002 S
008 C000002 801-22808
008 D010002 NEWARK
008 D020002 NJ
008 D030002 07102
008 D040002 4077
011 A000001 PRUDENTIAL INVESTMENT MANAGEMENT SERVICES LLC
011 B000001 8-36540
011 C010001 NEWARK
011 C020001 NJ
<PAGE> PAGE 2
011 C030001 07102
011 C040001 4077
012 A000001 PRUDENTIAL MUTUAL FUND SERVICES LLC
012 B000001 84-5681
012 C010001 NEW BRUNSWICK
012 C020001 NJ
012 C030001 08906
013 A000001 PRICEWATERHOUSECOOPERS LLP
013 B010001 NEW YORK
013 B020001 NY
013 B030001 10036
014 A000001 PRUDENTIAL SECURITIES INCORPORATED
014 B000001 8-27154
014 A000002 PRUCO SECURITIES CORPORATION
014 B000002 8-16402
014 A000003 PRUDENTIAL INVESTMENT MANAGEMENT SERVICES LLC
014 B000003 8-36540
015 A000001 STATE STREET BANK AND TRUST COMPANY
015 B000001 C
015 C010001 NORTH QUINCY
015 C020001 MA
015 C030001 02171
015 E010001 X
015 A000002 STATE STREET BANK AND TRUST CO.,LONDON BRANCH
015 B000002 S
015 C010002 LONDON
015 D010002 UNITED KINGDOM
015 E040002 X
015 A000003 CEDEL
015 B000003 S
015 C010003 LUXEMBOURG
015 D010003 LUXEMBOURG
015 E040003 X
015 A000004 THE EUROCLEAR SYSTEM
015 B000004 S
015 C010004 TRANSNATIONAL
015 D010004 TRANSNATIONAL
015 E040004 X
018 000000 Y
019 A000000 Y
019 B000000 104
019 C000000 PRUDENTIAL
020 C000001 0
020 C000002 0
020 C000003 0
020 C000004 0
020 C000005 0
020 C000006 0
020 C000007 0
020 C000008 0
020 C000009 0
<PAGE> PAGE 3
020 C000010 0
021 000000 0
022 A000001 GOLDMAN SACHS & CO.
022 B000001 13-5108880
022 C000001 6099417
022 D000001 326551
022 A000002 MORGAN (J.P.) SECURITIES, INC.
022 B000002 13-3224016
022 C000002 3954617
022 D000002 45237
022 A000003 BANK OF AMERICA NT & SA
022 B000003 94-1687665
022 C000003 3796599
022 D000003 0
022 A000004 SUNTRUST BANK
022 B000004 -
022 C000004 3750520
022 D000004 0
022 A000005 BANK OF MONTREAL
022 B000005 -
022 C000005 3505033
022 D000005 0
022 A000006 CHASE SECURITIES INC.
022 B000006 13-3112953
022 C000006 3064282
022 D000006 45103
022 A000007 SALOMON SMITH BARNEY INC.
022 B000007 11-2418191
022 C000007 2717737
022 D000007 34978
022 A000008 LEHMAN BROTHERS, INC.
022 B000008 13-2518466
022 C000008 2724237
022 D000008 13836
022 A000009 BANQUE NATIONALE DE PARIS
022 B000009 -
022 C000009 2537851
022 D000009 0
022 A000010 SOCIETE GENERALE SECURITIES CORP.
022 B000010 -
022 C000010 1841208
022 D000010 0
023 C000000 49631943
023 D000000 729392
024 000000 Y
025 A000001 SUNTRUST BANK
025 C000001 D
025 D000001 100000
025 A000002 SOCIETE GENERALE
025 C000002 D
025 D000002 95000
<PAGE> PAGE 4
025 A000003 BANQUE NATIONALE DE PARIS
025 C000003 D
025 D000003 95000
025 A000004 MORGAN (J.P.) SECURITIES, INC.
025 B000004 13-3224016
025 C000004 D
025 D000004 15000
025 D000005 0
025 D000006 0
025 D000007 0
025 D000008 0
026 A000000 N
026 B000000 N
026 C000000 N
026 D000000 Y
026 E000000 N
026 F000000 N
026 G010000 N
026 G020000 N
026 H000000 N
027 000000 Y
028 A010000 1135337
028 A020000 6372
028 A030000 0
028 A040000 996630
028 B010000 987699
028 B020000 5913
028 B030000 0
028 B040000 656121
028 C010000 2161723
028 C020000 9437
028 C030000 0
028 C040000 2215563
028 D010000 1826666
028 D020000 6415
028 D030000 0
028 D040000 1613905
028 E010000 1576530
028 E020000 8794
028 E030000 0
028 E040000 1480974
028 F010000 1530522
028 F020000 6803
028 F030000 0
028 F040000 1662933
028 G010000 9218477
028 G020000 43734
028 G030000 0
028 G040000 8626126
028 H000000 0
029 000000 N
<PAGE> PAGE 5
030 A000000 0
030 B000000 0.00
030 C000000 0.00
031 A000000 0
031 B000000 0
032 000000 0
033 000000 0
034 000000 N
035 000000 0
036 B000000 0
037 000000 N
038 000000 0
039 000000 N
040 000000 Y
041 000000 Y
042 A000000 0
042 B000000 0
042 C000000 0
042 D000000 100
042 E000000 0
042 F000000 0
042 G000000 0
042 H000000 0
043 000000 124
044 000000 0
045 000000 Y
046 000000 N
047 000000 Y
048 000000 0.200
048 A010000 0
048 A020000 0.000
048 B010000 0
048 B020000 0.000
048 C010000 0
048 C020000 0.000
048 D010000 0
048 D020000 0.000
048 E010000 0
048 E020000 0.000
048 F010000 0
048 F020000 0.000
048 G010000 0
048 G020000 0.000
048 H010000 0
048 H020000 0.000
048 I010000 0
048 I020000 0.000
048 J010000 0
048 J020000 0.000
048 K010000 0
048 K020000 0.000
<PAGE> PAGE 6
049 000000 N
050 000000 N
051 000000 N
052 000000 N
053 A000000 Y
053 B000000 Y
053 C000000 N
054 A000000 Y
054 B000000 Y
054 C000000 N
054 D000000 N
054 E000000 N
054 F000000 N
054 G000000 N
054 H000000 Y
054 I000000 N
054 J000000 Y
054 K000000 N
054 L000000 N
054 M000000 N
054 N000000 N
054 O000000 N
055 A000000 Y
055 B000000 N
056 000000 Y
057 000000 N
058 A000000 N
059 000000 Y
060 A000000 Y
060 B000000 Y
061 000000 0
062 A000000 Y
062 B000000 0.0
062 C000000 0.0
062 D000000 0.7
062 E000000 0.0
062 F000000 0.5
062 G000000 14.4
062 H000000 0.0
062 I000000 39.4
062 J000000 17.5
062 K000000 0.0
062 L000000 27.2
062 M000000 0.0
062 N000000 0.0
062 O000000 0.0
062 P000000 0.0
062 Q000000 0.0
062 R000000 0.0
063 A000000 69
063 B000000 0.0
<PAGE> PAGE 7
064 A000000 N
064 B000000 N
066 A000000 N
067 000000 N
068 A000000 N
068 B000000 N
069 000000 N
070 A010000 Y
070 A020000 Y
070 B010000 N
070 B020000 N
070 C010000 N
070 C020000 N
070 D010000 N
070 D020000 N
070 E010000 N
070 E020000 N
070 F010000 N
070 F020000 N
070 G010000 N
070 G020000 N
070 H010000 N
070 H020000 N
070 I010000 N
070 I020000 N
070 J010000 Y
070 J020000 Y
070 K010000 Y
070 K020000 N
070 L010000 Y
070 L020000 Y
070 M010000 N
070 M020000 N
070 N010000 Y
070 N020000 N
070 O010000 Y
070 O020000 N
070 P010000 Y
070 P020000 N
070 Q010000 N
070 Q020000 N
070 R010000 N
070 R020000 N
071 A000000 0
071 B000000 0
071 C000000 0
071 D000000 0
072 A000000 12
072 B000000 92925
072 C000000 0
072 D000000 0
<PAGE> PAGE 8
072 E000000 0
072 F000000 3435
072 G000000 0
072 H000000 0
072 I000000 250
072 J000000 146
072 K000000 0
072 L000000 60
072 M000000 12
072 N000000 531
072 O000000 0
072 P000000 0
072 Q000000 0
072 R000000 25
072 S000000 50
072 T000000 297
072 U000000 0
072 V000000 0
072 W000000 32
072 X000000 4838
072 Y000000 2136
072 Z000000 90224
072AA000000 35
072BB000000 2
072CC010000 0
072CC020000 0
072DD010000 12868
072DD020000 77388
072EE000000 0
073 A010000 0.0527
073 A020000 0.0532
073 B000000 0.0000
073 C000000 0.0000
074 A000000 0
074 B000000 15000
074 C000000 2089731
074 D000000 0
074 E000000 0
074 F000000 0
074 G000000 0
074 H000000 0
074 I000000 0
074 J000000 0
074 K000000 198
074 L000000 9250
074 M000000 11
074 N000000 2114190
074 O000000 0
074 P000000 8
074 Q000000 0
074 R010000 0
<PAGE> PAGE 9
074 R020000 0
074 R030000 0
074 R040000 2786
074 S000000 0
074 T000000 2111396
074 U010000 361167
074 U020000 1750229
074 V010000 1.00
074 V020000 1.00
074 W000000 0.9998
074 X000000 770
074 Y000000 0
075 A000000 1717554
075 B000000 0
076 000000 0.00
077 A000000 Y
077 B000000 Y
077 C000000 N
077 D000000 N
077 E000000 N
077 F000000 N
077 G000000 N
077 H000000 N
077 I000000 N
077 J000000 N
077 K000000 N
077 L000000 N
077 M000000 N
077 N000000 N
077 O000000 N
077 P000000 N
077 Q010000 Y
077 Q020000 N
077 Q030000 N
078 000000 N
080 A000000 ICI MUTUAL INSURANCE CO.
080 C000000 65000
081 A000000 Y
081 B000000 76
082 A000000 N
082 B000000 0
083 A000000 N
083 B000000 0
084 A000000 N
084 B000000 0
085 A000000 Y
085 B000000 N
086 A010000 0
086 A020000 0
086 B010000 0
086 B020000 0
<PAGE> PAGE 10
086 C010000 0
086 C020000 0
086 D010000 0
086 D020000 0
086 E010000 0
086 E020000 0
086 F010000 0
086 F020000 0
SIGNATURE GRACE TORRES
TITLE TREASURER
WARNING: THE EDGAR SYSTEM ENCOUNTERED ERROR(S) WHILE PROCESSING THIS SCHEDULE.
<TABLE> <S> <C>
<ARTICLE> 6
<CIK> 0000822337
<NAME> THE PRUDENTIAL INSTITUTIONAL LIQUIDITY PORTFOLIO
<SERIES>
<NUMBER> 001
<NAME> PRUDENTIAL INSTITUTIONAL LIQUIDITY PORTFOLIO CLASS A
<S> <C>
<PERIOD-TYPE> YEAR
<FISCAL-YEAR-END> MAR-31-1999
<PERIOD-END> MAR-31-1999
<INVESTMENTS-AT-COST> 0
<INVESTMENTS-AT-VALUE> 2,104,731,051
<RECEIVABLES> 9,447,386
<ASSETS-OTHER> 11,160
<OTHER-ITEMS-ASSETS> 0
<TOTAL-ASSETS> 2,114,189,597
<PAYABLE-FOR-SECURITIES> 0
<SENIOR-LONG-TERM-DEBT> 0
<OTHER-ITEMS-LIABILITIES> 2,793,673
<TOTAL-LIABILITIES> 2,793,673
<SENIOR-EQUITY> 0
<PAID-IN-CAPITAL-COMMON> 2,111,395,924
<SHARES-COMMON-STOCK> 2,111,395,924
<SHARES-COMMON-PRIOR> 1,051,207,362
<ACCUMULATED-NII-CURRENT> 0
<OVERDISTRIBUTION-NII> 0
<ACCUMULATED-NET-GAINS> 0
<OVERDISTRIBUTION-GAINS> 0
<ACCUM-APPREC-OR-DEPREC> 0
<NET-ASSETS> 2,111,395,924
<DIVIDEND-INCOME> 0
<INTEREST-INCOME> 92,925,412
<OTHER-INCOME> 0
<EXPENSES-NET> 2,701,429
<NET-INVESTMENT-INCOME> 90,223,983
<REALIZED-GAINS-CURRENT> 33,231
<APPREC-INCREASE-CURRENT> 0
<NET-CHANGE-FROM-OPS> 90,257,214
<EQUALIZATION> 0
<DISTRIBUTIONS-OF-INCOME> (90,257,214)
<DISTRIBUTIONS-OF-GAINS> 0
<DISTRIBUTIONS-OTHER> 0
<NUMBER-OF-SHARES-SOLD> 14,773,312,425
<NUMBER-OF-SHARES-REDEEMED> #############
<SHARES-REINVESTED> 78,273,080
<NET-CHANGE-IN-ASSETS> 1,060,188,562
<ACCUMULATED-NII-PRIOR> 0
<ACCUMULATED-GAINS-PRIOR> 0
<OVERDISTRIB-NII-PRIOR> 0
<OVERDIST-NET-GAINS-PRIOR> 0
<GROSS-ADVISORY-FEES> 3,435,107
<INTEREST-EXPENSE> 0
<GROSS-EXPENSE> 565,047
<AVERAGE-NET-ASSETS> 247,471,000
<PER-SHARE-NAV-BEGIN> 1.00
<PER-SHARE-NII> 0.053
<PER-SHARE-GAIN-APPREC> 0.00
<PER-SHARE-DIVIDEND> (0.053)
<PER-SHARE-DISTRIBUTIONS> 0.00
<RETURNS-OF-CAPITAL> 0.00
<PER-SHARE-NAV-END> 1.00
<EXPENSE-RATIO> 0.20
[AVG-DEBT-OUTSTANDING] 0
[AVG-DEBT-PER-SHARE] 0.00
</TABLE>
WARNING: THE EDGAR SYSTEM ENCOUNTERED ERROR(S) WHILE PROCESSING THIS SCHEDULE.
<TABLE> <S> <C>
<ARTICLE> 6
<CIK> 0000822337
<NAME> THE PRUDENTIAL INSTITUTIONAL LIQUIDITY PORTFOLIO
<SERIES>
<NUMBER> 004
<NAME> PRUDENTIAL INSTITUTIONAL LIQUIDITY PORTFOLIO CLASS I
<S> <C>
<PERIOD-TYPE> YEAR
<FISCAL-YEAR-END> MAR-31-1999
<PERIOD-END> MAR-31-1999
<INVESTMENTS-AT-COST> 0
<INVESTMENTS-AT-VALUE> 2,104,731,051
<RECEIVABLES> 9,447,386
<ASSETS-OTHER> 11,160
<OTHER-ITEMS-ASSETS> 0
<TOTAL-ASSETS> 2,114,189,597
<PAYABLE-FOR-SECURITIES> 0
<SENIOR-LONG-TERM-DEBT> 0
<OTHER-ITEMS-LIABILITIES> 2,793,673
<TOTAL-LIABILITIES> 2,793,673
<SENIOR-EQUITY> 0
<PAID-IN-CAPITAL-COMMON> 2,111,395,924
<SHARES-COMMON-STOCK> 2,111,395,924
<SHARES-COMMON-PRIOR> 1,051,207,362
<ACCUMULATED-NII-CURRENT> 0
<OVERDISTRIBUTION-NII> 0
<ACCUMULATED-NET-GAINS> 0
<OVERDISTRIBUTION-GAINS> 0
<ACCUM-APPREC-OR-DEPREC> 0
<NET-ASSETS> 2,111,395,924
<DIVIDEND-INCOME> 0
<INTEREST-INCOME> 92,925,412
<OTHER-INCOME> 0
<EXPENSES-NET> 2,701,429
<NET-INVESTMENT-INCOME> 90,223,983
<REALIZED-GAINS-CURRENT> 33,231
<APPREC-INCREASE-CURRENT> 0
<NET-CHANGE-FROM-OPS> 90,257,214
<EQUALIZATION> 0
<DISTRIBUTIONS-OF-INCOME> (90,257,214)
<DISTRIBUTIONS-OF-GAINS> 0
<DISTRIBUTIONS-OTHER> 0
<NUMBER-OF-SHARES-SOLD> 14,773,312,425
<NUMBER-OF-SHARES-REDEEMED> #############
<SHARES-REINVESTED> 78,273,080
<NET-CHANGE-IN-ASSETS> 1,060,188,562
<ACCUMULATED-NII-PRIOR> 0
<ACCUMULATED-GAINS-PRIOR> 0
<OVERDISTRIB-NII-PRIOR> 0
<OVERDIST-NET-GAINS-PRIOR> 0
<GROSS-ADVISORY-FEES> 3,435,107
<INTEREST-EXPENSE> 0
<GROSS-EXPENSE> 565,047
<AVERAGE-NET-ASSETS> 1,470,082,000
<PER-SHARE-NAV-BEGIN> 1
<PER-SHARE-NII> 0.053
<PER-SHARE-GAIN-APPREC> 0
<PER-SHARE-DIVIDEND> (0)
<PER-SHARE-DISTRIBUTIONS> 0.000
<RETURNS-OF-CAPITAL> 0
<PER-SHARE-NAV-END> 1
<EXPENSE-RATIO> 0
[AVG-DEBT-OUTSTANDING] 0
[AVG-DEBT-PER-SHARE] 0
</TABLE>
To the Shareholders and Board of Directors of
Prudential Institutional Liquidity Portfolio, Inc. -
Institutional Money Market Series
(2)
Report of Independent Accountants
To the Shareholders and Board of Directors of
Prudential Institutional Liquidity Portfolio, Inc. -
Institutional Money Market Series
In planning and performing our audit of the financial
statements of Prudential Institutional Liquidity Portfolio,
Inc. - Institutional Money Market Series (the "Fund") for the
year ended March 31, 1999, we considered its internal control,
including control activities for safeguarding securities, in
order to determine our auditing procedures for the purpose of
expressing our opinion on the financial statements and to
comply with the requirements of Form N-SAR, not to provide
assurance on internal control.
The management of the Fund is responsible for establishing and
maintaining internal control. In fulfilling this
responsibility, estimates and judgments by management are
required to assess the expected benefits and related costs of
controls. Generally, controls that are relevant to an audit
pertain to the entity's objective of preparing financial
statements for external purposes that are fairly presented in
conformity with generally accepted accounting principles.
Those controls include the safeguarding of assets against
unauthorized acquisition, use or disposition.
Because of inherent limitations in internal control, errors or
fraud may occur and not be detected. Also, projection of any
evaluation of internal control to future periods is subject to
the risk that it may become inadequate because of changes in
conditions or that the effectiveness of the design and
operation may deteriorate.
Our consideration of internal control would not necessarily
disclose all matters in internal control that might be material
weaknesses under standards established by the American
Institute of Certified Public Accountants. A material weakness
is a condition in which the design or operation of one or more
of the internal control components does not reduce to a
relatively low level the risk that misstatements caused by
error or fraud in amounts that would be material in relation to
the financial statements being audited may occur and not be
detected within a timely period by employees in the normal
course of performing their assigned functions. However, we
noted no matters involving internal control and its operation,
including controls for safeguarding securities, that we
consider to be material weaknesses as defined above as of March
31, 1999.
This report is intended solely for the information and use of
management and the Board of Directors of the Fund and the
Securities and Exchange Commission.
PricewaterhouseCoopers LLP
New York, New York
May 20, 1999
