PROSPECTUS Dated May 5, 1999                        Pricing Supplement No. 32 to
PROSPECTUS SUPPLEMENT                       Registration Statement No. 333-75289
Dated May 6, 1999                                              December 28, 1999
                                                                  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.

Principal Amount:          $575,000,000

Maturity Date:             December 18, 2000

Interest Accrual Date:     December 30, 1999

Interest Payment Dates:    March 30, 2000, June 30, 2000, September 29, 2000
                           and the Maturity Date

Initial Interest Rate:     6.20375%

Base Rate:                 LIBOR

Index Maturity:            3 Months

Spread
(Plus or Minus):           Plus 0.02% per annum

Index Currency:            U.S. Dollars

Interest Payment Period:   Quarterly

Specified Currency:        U.S. Dollars

Issue Price:               100%


Settlement Date
  (Original Issue Date):   December 30, 1999

Initial Interest Reset
  Date:                    March 30, 2000

Interest Reset Dates:      Same as Interest Payment Dates

Interest Reset Period:     Quarterly

Interest Determination
  Dates:                   Two London banking days prior to each
                           Interest Reset Date

Reporting Service:         Telerate (Page 3750)

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:                     61745ENW7


Terms not defined above have the meanings given to such terms in the
accompanying prospectus supplement.

                           MORGAN STANLEY DEAN WITTER