PROSPECTUS Dated May 5, 1999 Pricing Supplement No. 51 to
PROSPECTUS SUPPLEMENT Registration Statement No. 333-75289
Dated May 6, 1999 March 13, 2000
Rule 424(b)(3)
Morgan Stanley Dean Witter & Co.
MEDIUM-TERM NOTES, SERIES C
Senior Floating Rate Notes
-----------------------
We will not redeem these Medium-Term Notes, Series C (Senior Floating Rate
Notes) prior to the maturity date. We describe the basic features of this type
of note in the section called "Description of Notes--Floating Rate Notes" in
the accompanying prospectus supplement, subject to and as modified by the
provisions described below. The notes are "short-term discount notes" as
defined in the accompanying prospectus supplement under the caption "United
States Federal Taxation--Notes--Discount Notes."
Principal Amount: $50,000,000
Maturity Date: March 16, 2001
Interest Accrual Date: March 16, 2000
Interest Payment Dates: Each March 16, June 16, September 16 and December
16, commencing June 16, 2000
Initial Interest Rate: To be determined on the interest determination
date with respect to the week including the
Original Issue Date. See "Description of
Notes--Floating Rate Notes--How Floating Interest
Rates Are Reset" in the accompanying prospectus
supplement
Base Rate: Treasury rate
Index Maturity: 3 Months
Spread (Plus or Minus): Plus 0.47% per annum
Index Currency: N/A
Interest Payment Period: Quarterly
Specified Currency: U.S. Dollars
Issue Price: 100%
Settlement Date
(Original Issue Date): March 16, 2000
Initial Interest Reset Date: The interest reset date with respect to the week
following the week including the Original Issue
Date, scheduled to be March 21, 2000
Interest Reset Dates: The day in each week following the day on which
Treasury bills are sold at auction. See
"Description of Notes--Floating Rate Notes--How
Floating Interest Rates Are Reset" in the
accompanying prospectus supplement
Interest Reset Period: Weekly
Interest Determination Dates: The day of the week in which an interest reset
date falls on which Treasury bills would normally
be auctioned. See "Description of Notes--Floating
Rate Notes--How Floating Interest Rates Are
Reset" in the accompanying prospectus supplement
Reporting Service: Telerate Page 56
Book Entry Note or
Certificated Note: Book Entry Note
Senior Note or
Subordinated Note: Senior Note
Agent: Morgan Stanley & Co. Incorporated
Calculation Agent: The Chase Manhattan Bank
Minimum Denomination: $1,000
CUSIP: 61745EPJ4
Capitalized terms not defined above have the meanings given to such terms
in the accompanying prospectus supplement.
MORGAN STANLEY DEAN WITTER
