As filed with the Securities and Exchange Commission on January 24, 2000
                                                  Registration No. 333-
================================================================================
                       SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549
                     --------------------------------------
                                    FORM S-8
                        REGISTRATION STATEMENT UNDER THE
                             SECURITIES ACT OF 1933
                            -------------------------
                        MORGAN STANLEY DEAN WITTER & CO.
             (Exact name of Registrant as specified in its charter)

            Delaware                                        36-3145972
 (State or other jurisdiction of                         (I.R.S. Employer
 incorporation or organization)                       Identification Number)

                                  1585 Broadway
                            New York, New York 10036
                    (Address of Principal Executive Offices)

                          -----------------------------
              MORGAN STANLEY DEAN WITTER -- CABOT AIRCRAFT SERVICES
                               PROFIT SHARING PLAN
                            (Full title of the plan)

                              Donald G. Kempf, Jr.
           Chief Legal Officer, Executive Vice President and Secretary
                                  1585 Broadway
                            New York, New York 10036
                     (Name and address of agent for service)

                                 (212) 761-4000
          (Telephone number, including area code, of agent for service)

                         CALCULATION OF REGISTRATION FEE
<TABLE>
<CAPTION>
------------------------------------------------------------------------------------------------------------------------
       Title of                  Amount             Proposed Maximum        Proposed Maximum
   Securities to be               to be            Offering Price Per           Aggregate               Amount of
      Registered              Registered(1)             Share(2)            Offering Price(2)        Registration Fee
------------------------------------------------------------------------------------------------------------------------
<S>                           <C>                      <C>                      <C>                      <C>
Common Stock, par             15,000 shares            $133.125                 $1,996,875               $527.18
value $0.01 per share(3)
------------------------------------------------------------------------------------------------------------------------
</TABLE>
(1)      There are also registered hereby such indeterminate number of shares of
         Common Stock as may become issuable by reason of the anti-dilution
         provisions of the plan. No additional registration fee is included for
         these shares.

(2)      The Proposed Maximum Offering Price Per Share and the Proposed Maximum
         Aggregate offering Price are based on the average of the high and low
         prices of the Common Stock as reported on the Consolidated Transaction
         Reporting System for January 21, 2000, in accordance with Rule 457(h)
         and (c) under the Securities Act of 1933 and are utilized solely for
         the purpose of calculating the registration fee.

(3)      This Registration Statement also covers the associated preferred stock
         purchase rights (the "Rights") issued pursuant to a Rights Agreement,
         dated as of April 25, 1995 and amended as of February 4, 1997 and June
         15, 1999, between the Registrant and The Chase Manhattan Bank (formerly
         Chemical Bank), as Rights Agent. Prior to the occurrence of certain
         events, the Rights will not be exercisable or evidenced separately from
         the Registrant's Common Stock.


<PAGE>
                                       2



                                     Part I

              INFORMATION REQUIRED IN THE SECTION 10(a) PROSPECTUS

                  The documents containing information specified in Part I (plan
information and registrant information) will be sent or given to employees as
specified by Rule 428(b)(1). Such documents need not be filed with the
Securities and Exchange Commission either as part of this registration statement
or as prospectuses or prospectus supplements pursuant to Rule 424. These
documents and the documents incorporated by reference in this registration
statement pursuant to Item 3 of Part II of this form taken together constitute a
prospectus that meets the requirements of Section 10(a) of the Securities Act of
1933.


<PAGE>


                                        3

                                     Part II

               INFORMATION REQUIRED IN THE REGISTRATION STATEMENT

Item 3.           Incorporation of Documents by Reference.

                  The Registrant incorporates the following documents herein by
reference:

                  (a) The Registrant's Annual Report on Form 10-K for the fiscal
         year ended November 30, 1998;

                  (b) The Registrant's Quarterly Reports on Form 10-Q for the
         fiscal quarters ended February 28, 1999; May 31, 1999 and August 31,
         1999;

                  (c) The Registrant's Current Reports on Form 8-K dated
         January 7, 1999; January 12, 1999; March 25, 1999; May 6, 1999 (as
         amended by Form 8-K/A filed May 12, 1999); June 15, 1999; June 24,
         1999; September 22, 1999; and October 20, 1999 and December 20, 1999
         (two reports);

                  (d) The description of the Registrant's Common Stock
         contained in the Registrant's Registration Statement on Form 10 filed
         with the Securities Exchange Commission pursuant to Section 12 of the
         Securities Exchange Act of 1934 on January 15, 1993, as amended by the
         description contained in the Registrant's Forms 8 dated February 11,
         February 21 and February 22, 1993;

                  (e) The description of the Registrant's Shareholder
         Rights Agreement contained in the Registrant's Registration Statement
         on Form 8-A/A filed with the Securities Exchange Commission pursuant to
         Section 12 of the Securities Exchange Act of 1934 on June 29, 1999;

All documents subsequently filed by the Registrant pursuant to Sections 13(a),
13(c), 14 and 15(d) of the Securities Exchange Act of 1934, prior to the filing
of a post-effective amendment which indicates that all securities offered have
been sold or which deregisters all securities then remaining unsold, shall be
deemed to be incorporated by reference in the Registration Statement and to be
part thereof from the date of filing of such documents. Any statement contained
in a document incorporated or deemed to be incorporated by reference herein
shall be deemed to be modified or superseded for purposes of this Registration
Statement to the extent that a statement incorporated by reference herein
modifies or supersedes such statement. Any such statement so modified or
superseded shall not be deemed, except as so modified or superseded, to
constitute a part of this Registration Statement.

Item 4.           Description of Securities.

                  Not applicable.


<PAGE>


                                        4

Item 5.           Interests of Named Experts and Counsel.

                  Not applicable.

Item 6.           Indemnification of Directors and Officers.

                  Article VIII of the Amended and Restated Certificate of
Incorporation of the Registrant (the "Certificate of Incorporation") and Section
6.07 of the Amended and Restated By-laws of the Registrant (the "By-laws"), each
as amended to date, provide for the indemnification of the Registrant's
directors and officers. The Certificate of Incorporation provides that any
person who is a director or officer of the Registrant shall be indemnified by
the Registrant to the fullest extent permitted from time to time by applicable
law. In addition, the By-laws provide that each person who was or is made a
party or is threatened to be made a party to or is involved in any threatened,
pending or completed action, suit or proceeding, whether civil, criminal,
administrative or investigative, by reason of the fact that he or she or a
person of whom he or she is the legal representative is or was a director or
officer of the Registrant or a director or elected officer of a corporation a
majority of the capital stock (other than directors' qualifying shares) of which
is owned directly or indirectly by the Registrant (a "Subsidiary") shall be
indemnified by the Registrant to the fullest extent permitted by applicable law.
The right to indemnification under the By-laws includes the right to be paid the
expenses incurred in defending a proceeding in advance of its final disposition
upon receipt (unless the Registrant upon authorization of the Board of Directors
waives said requirement to the extent permitted by applicable law) of an
undertaking by or on behalf of such person to repay such amount if it shall
ultimately be determined that such person is not entitled to be indemnified by
the Registrant.

                  The Registrant's By-laws also provide that the Registrant may,
to the extent authorized from time to time by the Board of Directors, provide
rights to indemnification, and rights to be paid by the Registrant the expenses
incurred in defending any proceeding in advance of its final disposition, to any
person who is or was an employee or agent (other than a director or officer) of
the Registrant or a Subsidiary and to any person who is or was serving at the
request of the Registrant or a Subsidiary as a director, officer, partner,
member, employee or agent of another corporation, partnership, limited liability
company, joint venture, trust or other enterprise at the request of the
Registrant or a Subsidiary, to the same extent as the By-laws provide with
respect to indemnification of, and advancement of expenses for, directors and
officers of the Registrant.

                  Under the By-laws, the Registrant has the power to purchase
and maintain insurance on behalf of any person who is or was a director,
officer, partner, member, employee or agent of the Registrant or of its
subsidiary, or of another corporation, partnership, limited liability company,
joint venture, trust or other enterprise, against any expense, liability or loss
whether or not the Registrant or its subsidiary would have the power to
indemnify that person against that expense, liability or loss under the
provisions of applicable law.


<PAGE>


                                        5

                  The Registrant has in effect insurance policies in the amount
of $125 million for general officers' and directors' liability insurance and $25
million for fiduciary liability insurance covering all of our directors and
officers in some of the instances where by law they may not be indemnified by
the Registrant.

Item 7.           Exemption from Registration Claimed.

                  Not applicable.

Item 8.           Exhibits.

                  The following exhibits are filed as part of this Registration
                  Statement:

                  4.1               Form of Trust Deed and Rules of the Morgan
                                    Stanley Dean Witter -- Cabot Aircraft
                                    Services Profit Sharing Plan.

                  4.2               Amended and Restated Certificate of
                                    Incorporation. Filed as Exhibit 3.1 to the
                                    Registrant's Annual Report on Form 10-K for
                                    the fiscal year ended November 30, 1998 and
                                    incorporated herein by reference.

                  4.3               Certificate of Elimination of the 7.80%
                                    Cumulative Preferred Stock ($200.00 Stated
                                    Value) of the Registrant. File as Exhibit
                                    3.2 to the Registrant's Quarterly Report on
                                    Form 10-Q for the quarter ended February 28,
                                    1999 and incorporated herein by reference.

                  4.4               Certificate of Elimination of the 7.82%
                                    Cumulative Preferred Stock ($200.00 Stated
                                    Value) of the Registrant. Filed as Exhibit
                                    3.3 to the Registrant's Quarterly Report on
                                    Form 10-Q for the quarter ended February 28,
                                    1999 and incorporated herein by
                                    reference.

                  4.5               By-Laws, as amended to date. Filed as
                                    Exhibit 3.4 to the Registrant's Quarterly
                                    Report on Form 10-Q for the quarter ended
                                    February 28, 1999 and incorporated herein by
                                    reference.

                  4.6               Rights Agreement dated as of April 25, 1995
                                    between the Registrant and Chemical Bank, as
                                    rights agent, which includes as Exhibit B
                                    thereto the Form of Rights Certificate.
                                    Filed as Exhibit 1 to the Registrant's
                                    Registration Statement on Form 8-A dated
                                    April 26, 1995 and incorporated herein by
                                    reference.

                  4.7               Amendment dated as of February 4, 1997 to
                                    the Rights Agreement between the Registrant
                                    and The Chase Manhattan Bank (as


<PAGE>


                                        6

                                    successor to Chemical Bank), as rights
                                    agent. Filed as Exhibit 4.1 to the
                                    Registrant's Current Report on Form 8-K
                                    dated February 4, 1997 and incorporated
                                    herein by reference.

                  4.8               Second Amendment, dated as of June 15, 1999,
                                    to the Rights Agreement dated as of April
                                    25, 1995, between Morgan Stanley Dean Witter
                                    & Co. (formerly Dean Witter, Discover & Co.)
                                    and Chase Manhattan Bank (formerly Chemical
                                    Bank), as rights agent Filed as Exhibit 4.3
                                    to the Registrant's Registration Statement
                                    on Form 8A/A dated June 29, 1999 and
                                    incorporated herein by reference.

                  15.1              Letter of Awareness from Deloitte & Touche
                                    LLP.

                  23.1              Consent of Deloitte & Touche LLP.

                  23.2              Consent of Ernst & Young LLP.

                  24.1              Powers of Attorney (included on signature
                                    page).

The shares of Common Stock registered hereby are not original issuance
securities. Pursuant to Item 8(a) of Part II of Form S-8, an opinion of counsel
as to the legality of the shares accordingly is not required.

Item 9.           Undertakings.

                  (a) The undersigned Registrant hereby undertakes;

                  (1) To file, during any period in which offers or sales
         are being made, a post-effective amendment to this registration
         statement:

                           (i) to include any prospectus required by Section
                  10(a)(3) of the Securities Act of 1933;

                           (ii) to reflect in the prospectus any facts or events
                  arising after the effective date of the registration statement
                  (or the most recent post-effective amendment thereof) which,
                  individually or in aggregate, represent a fundamental change
                  in the information set forth in this Registration Statement;
                  and

                           (iii) to include any material information with
                  respect to the plan of distribution not previously disclosed
                  in this Registration Statement or any material change to such
                  information in the Registration Statement;


<PAGE>


                                        7

         provided, however, that the undertakings set forth in paragraphs (1)(i)
         and (1)(ii) above do not apply if the information required to be
         included in a post-effective amendment by those paragraphs is contained
         in periodic reports filed by the Registrant pursuant to Section 13 or
         Section 15(d) of the Securities Exchange Act of 1934 that are
         incorporated by reference in this Registration Statement;

                  (2) That, for the purpose of determining any liability
         under the Securities Act of 1933, each such post-effective amendment
         shall be deemed to be a new registration statement relating to the
         securities offered therein, and the offering of such securities at that
         time shall be deemed to be the initial bona fide offering thereof; and

                  (3) To remove from registration by means of a
         post-effective amendment any of the securities being registered which
         remain unsold at the termination of the offering.

                  (b) The undersigned Registrant hereby further
undertakes that, for purposes of determining any liability under the Securities
Act of 1933, each filing of the Registrant's annual report pursuant to Section
13(a) or Section 15(d) of the Securities Exchange Act of 1934 (and, where
applicable, each filing of an employee benefit plan's annual report pursuant to
Section 15(d) of the Securities Exchange Act of 1934) that is incorporated by
reference in this Registration Statement shall be deemed to be a new
registration statement relating to the securities offered therein, and the
offering of such securities at the time shall be deemed to be the initial bona
fide offering thereof.

                  (c) Insofar as indemnification for liabilities arising
under the Securities Act of 1933 may be permitted to directors, officers and
controlling persons of the Registrant pursuant to the foregoing provisions, or
otherwise, the Registrant has been advised that in the opinion of the Securities
and Exchange Commission such indemnification is against public policy as
expressed in the Securities Act of 1933 and is, therefore, unenforceable. In the
event that a claim for indemnification against such liabilities (other than the
payment by the Registrant of expenses incurred or paid by a director, officer or
controlling person of the Registrant in the successful defense of any action,
suit or proceeding) is asserted by such director, officer or controlling person
in connection with the securities being registered, the Registrant will, unless
in the opinion of its counsel the matter has been settled by controlling
precedent, submit to a court of appropriate jurisdiction the question whether
such indemnification by it is against public policy as expressed in the
Securities Act of 1933 and will be governed by the final adjudication of such
issue.


<PAGE>


                                        8

                                   SIGNATURES

                  Pursuant to the requirements of the Securities Act of 1933, as
amended, the Registrant certifies that it has reasonable grounds to believe that
it meets all of the requirements for filing on Form S-8 and has duly caused this
Registration Statement to be signed on its behalf by the undersigned, thereunto
duly authorized, in the City of New York, State of New York on the 24th day of
January, 2000.

                                    MORGAN STANLEY DEAN WITTER & CO.
                                    (Registrant)

                                    By:  /s/ Phillip J. Purcell
                                    -------------------------------------
                                    Philip J. Purcell
                                    Chairman of the Board and
                                    Chief Executive Officer


<PAGE>


                                        9

                                POWER OF ATTORNEY

                  KNOW ALL PERSONS BY THESE PRESENTS that each person whose
signature appears below hereby constitutes and appoints Robert G. Scott, Ronald
T. Carman, Donald G. Kempf Jr., Ralph L. Pellecchio, Martin M. Cohen and William
J. O'Shaughnessy, Jr. and each of them singly, his or her true and lawful
attorney-in-fact and agent with full power of substitution and resubstitution,
for him or her and in his or her name, place and stead, in any and all
capacities, to sign any and all amendments, including post-effective amendments,
to this Registration Statement (any of which amendments may make such changes
and additions to this Registration Statement as such attorneys-in-fact may deem
necessary or appropriate) and to file the same, with all exhibits thereto, and
any other documents that may be required in connection therewith, granting unto
said attorneys-in-fact and agents full power and authority to be done in and
about the premises, as fully to all intents and purposes as he or she might or
could do in person, hereby ratifying and confirming all that said
attorneys-in-fact and agents, or their substitutes, may lawfully do or cause to
be done by virtue hereof.

                  Pursuant to the requirements of the Securities Act of 1933, as
amended, this Registration Statement has been signed by the following persons in
the capacities indicated on the 24th day of January, 2000.

       SIGNATURE                                TITLE

                                       Chairman of the Board and
/s/ Philip J. Purcell                  Chief Executive Officer
------------------------
Philip J. Purcell

                                       President, Chief Operating
/s/ John J. Mack                       Officer and Director
------------------------
John J. Mack

                                       Executive Vice President and Chief
/s/ Robert G. Scott                    Financial Officer (Principal Financial
------------------------               Officer)
Robert G. Scott

                                       Controller (Principal Accounting Officer)
/s/ Joanne Pace
------------------------
Joanne Pace

/s/ Robert P. Bauman                   Director
------------------------
Robert P. Bauman


/s/ Edward A. Brennan                  Director
------------------------
Edward A. Brennan


<PAGE>


                                       10

/s/ Diana D. Brooks                     Director
------------------------
Diana D. Brooks

/s/ Daniel B. Burke                     Director
------------------------
Daniel B. Burke


------------------------                Director
C. Robert Kidder

/s/ Charles F. Knight                   Director
------------------------
Charles F. Knight

/s/ Miles L. Marsh                      Director
------------------------
Miles L. Marsh

/s/ Michael A. Miles                    Director
------------------------
Michael A. Miles

/s/ Allen E. Murray                     Director
------------------------
Allen E. Murray

/s/ Clarence B. Rogers, Jr.             Director
------------------------
Clarence B. Rogers, Jr.

/s/ Laura D'Andrea Tyson                Director
------------------------
Laura D'Andrea Tyson




<PAGE>


                                       11

                                  Exhibit Index

         Exhibit No.                   Description of Document

         *4.1              Form of Trust Deed and Rules of the Morgan Stanley
                           Dean Witter -- Cabot Aircraft Services Profit Sharing
                           Plan.

         4.2               Amended and Restated Certificate of Incorporation.
                           Filed as Exhibit 3.1 to the Registrant's Annual
                           Report on Form 10-K for the fiscal year ended
                           November 30, 1998 and incorporated herein by
                           reference.

         4.3               Certificate of Elimination of the 7.80% Cumulative
                           Preferred Stock ($200.00 Stated Value) of the
                           Registrant. File as Exhibit 3.2 to the Registrant's
                           Quarterly Report on Form 10-Q for the quarter ended
                           February 28, 1999 and incorporated herein by
                           reference.

         4.4               Certificate of Elimination of the 7.82% Cumulative
                           Preferred Stock ($200.00 Stated Value) of the
                           Registrant. Filed as Exhibit 3.3 to the Registrant's
                           Quarterly Report on Form 10-Q for the quarter ended
                           February 28, 1999 and incorporated herein by
                           reference.

         4.5               By-Laws, as amended to date. Filed as Exhibit 3.4 to
                           the Registrant's Quarterly Report on Form 10-Q for
                           the quarter ended February 28, 1999 and incorporated
                           herein by reference.

         4.6               Rights Agreement dated as of April 25, 1995 between
                           the Registrant and Chemical Bank, as rights agent,
                           which includes as Exhibit B thereto the Form of
                           Rights Certificate. Filed as Exhibit 1 to the
                           Registrant's Registration Statement on Form 8-A dated
                           April 26, 1995 and incorporated herein by reference.

         4.7               Amendment dated as of February 4, 1997 to the Rights
                           Agreement between the Registrant and The Chase
                           Manhattan Bank (as successor to Chemical Bank), as
                           rights agent. Filed as Exhibit 4.1 to the
                           Registrant's Current Report on Form 8-K dated
                           February 4, 1997 and incorporated herein by
                           reference.

         4.8               Second Amendment, dated as of June 15, 1999, to the
                           Rights Agreement dated as of April 25, 1995, between
                           Morgan Stanley Dean Witter & Co. (formerly Dean
                           Witter, Discover & Co.) and Chase Manhattan Bank
                           (formerly Chemical Bank), as rights agent Filed as
                           Exhibit 4.3 to the Registrant's Registration
                           Statement on Form 8A/A dated June 29, 1999 and
                           incorporated herein by reference.


<PAGE>


                                       12

         *15.1             Letter of Awareness from Deloitte & Touche LLP.

         *23.1             Consent of Deloitte & Touche LLP.

         *23.2             Consent of Ernst & Young LLP.

         *24.1             Powers of Attorney (included on signature page).

--------------------
*    Filed Herewith
[{"type": "S-8", "sequence": "1", "description": "FORM S-8", "secsgml_size_bytes": 28020}]
{"company-data": {"conformed-name": "MORGAN STANLEY DEAN WITTER & CO", "cik": "0000895421", "assigned-sic": "6199", "irs-number": "363145972", "state-of-incorporation": "DE", "fiscal-year-end": "1130"}, "filing-values": {"form-type": "S-8", "act": "33", "file-number": "333-95303", "film-number": "512184"}, "business-address": {"street1": "1585 BROADWAY", "city": "NEW YORK", "state": "NY", "zip": "10036", "phone": "2127614000"}, "mail-address": {"street1": "1585 BROADWAY", "street2": "38TH FLOOR", "city": "NEW YORK", "state": "NY", "zip": "10036"}, "former-company": {"former-conformed-name": "DEAN WITTER DISCOVER & CO", "date-changed": "19960315"}}
As filed with the Securities and Exchange Commission on January 24, 2000
                                                  Registration No. 333-
================================================================================
                       SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549
                     --------------------------------------
                                    FORM S-8
                        REGISTRATION STATEMENT UNDER THE
                             SECURITIES ACT OF 1933
                            -------------------------
                        MORGAN STANLEY DEAN WITTER & CO.
             (Exact name of Registrant as specified in its charter)

            Delaware                                        36-3145972
 (State or other jurisdiction of                         (I.R.S. Employer
 incorporation or organization)                       Identification Number)

                                  1585 Broadway
                            New York, New York 10036
                    (Address of Principal Executive Offices)

                          -----------------------------
              MORGAN STANLEY DEAN WITTER -- CABOT AIRCRAFT SERVICES
                               PROFIT SHARING PLAN
                            (Full title of the plan)

                              Donald G. Kempf, Jr.
           Chief Legal Officer, Executive Vice President and Secretary
                                  1585 Broadway
                            New York, New York 10036
                     (Name and address of agent for service)

                                 (212) 761-4000
          (Telephone number, including area code, of agent for service)

                         CALCULATION OF REGISTRATION FEE
------------------------------------------------------------------------------------------------------------------------
       Title of                  Amount             Proposed Maximum        Proposed Maximum
   Securities to be               to be            Offering Price Per           Aggregate               Amount of
      Registered              Registered(1)             Share(2)            Offering Price(2)        Registration Fee
------------------------------------------------------------------------------------------------------------------------
Common Stock, par             15,000 shares            $133.125                 $1,996,875               $527.18
value $0.01 per share(3)
------------------------------------------------------------------------------------------------------------------------
(1)      There are also registered hereby such indeterminate number of shares of
         Common Stock as may become issuable by reason of the anti-dilution
         provisions of the plan. No additional registration fee is included for
         these shares.

(2)      The Proposed Maximum Offering Price Per Share and the Proposed Maximum
         Aggregate offering Price are based on the average of the high and low
         prices of the Common Stock as reported on the Consolidated Transaction
         Reporting System for January 21, 2000, in accordance with Rule 457(h)
         and (c) under the Securities Act of 1933 and are utilized solely for
         the purpose of calculating the registration fee.

(3)      This Registration Statement also covers the associated preferred stock
         purchase rights (the "Rights") issued pursuant to a Rights Agreement,
         dated as of April 25, 1995 and amended as of February 4, 1997 and June
         15, 1999, between the Registrant and The Chase Manhattan Bank (formerly
         Chemical Bank), as Rights Agent. Prior to the occurrence of certain
         events, the Rights will not be exercisable or evidenced separately from
         the Registrant's Common Stock.
2

                                     Part I

              INFORMATION REQUIRED IN THE SECTION 10(a) PROSPECTUS

                  The documents containing information specified in Part I (plan
information and registrant information) will be sent or given to employees as
specified by Rule 428(b)(1). Such documents need not be filed with the
Securities and Exchange Commission either as part of this registration statement
or as prospectuses or prospectus supplements pursuant to Rule 424. These
documents and the documents incorporated by reference in this registration
statement pursuant to Item 3 of Part II of this form taken together constitute a
prospectus that meets the requirements of Section 10(a) of the Securities Act of
1933.
3

                                     Part II

               INFORMATION REQUIRED IN THE REGISTRATION STATEMENT

Item 3.           Incorporation of Documents by Reference.

                  The Registrant incorporates the following documents herein by
reference:

                  (a) The Registrant's Annual Report on Form 10-K for the fiscal
         year ended November 30, 1998;

                  (b) The Registrant's Quarterly Reports on Form 10-Q for the
         fiscal quarters ended February 28, 1999; May 31, 1999 and August 31,
         1999;

                  (c) The Registrant's Current Reports on Form 8-K dated
         January 7, 1999; January 12, 1999; March 25, 1999; May 6, 1999 (as
         amended by Form 8-K/A filed May 12, 1999); June 15, 1999; June 24,
         1999; September 22, 1999; and October 20, 1999 and December 20, 1999
         (two reports);

                  (d) The description of the Registrant's Common Stock
         contained in the Registrant's Registration Statement on Form 10 filed
         with the Securities Exchange Commission pursuant to Section 12 of the
         Securities Exchange Act of 1934 on January 15, 1993, as amended by the
         description contained in the Registrant's Forms 8 dated February 11,
         February 21 and February 22, 1993;

                  (e) The description of the Registrant's Shareholder
         Rights Agreement contained in the Registrant's Registration Statement
         on Form 8-A/A filed with the Securities Exchange Commission pursuant to
         Section 12 of the Securities Exchange Act of 1934 on June 29, 1999;

All documents subsequently filed by the Registrant pursuant to Sections 13(a),
13(c), 14 and 15(d) of the Securities Exchange Act of 1934, prior to the filing
of a post-effective amendment which indicates that all securities offered have
been sold or which deregisters all securities then remaining unsold, shall be
deemed to be incorporated by reference in the Registration Statement and to be
part thereof from the date of filing of such documents. Any statement contained
in a document incorporated or deemed to be incorporated by reference herein
shall be deemed to be modified or superseded for purposes of this Registration
Statement to the extent that a statement incorporated by reference herein
modifies or supersedes such statement. Any such statement so modified or
superseded shall not be deemed, except as so modified or superseded, to
constitute a part of this Registration Statement.

Item 4.           Description of Securities.

                  Not applicable.
4

Item 5.           Interests of Named Experts and Counsel.

                  Not applicable.

Item 6.           Indemnification of Directors and Officers.

                  Article VIII of the Amended and Restated Certificate of
Incorporation of the Registrant (the "Certificate of Incorporation") and Section
6.07 of the Amended and Restated By-laws of the Registrant (the "By-laws"), each
as amended to date, provide for the indemnification of the Registrant's
directors and officers. The Certificate of Incorporation provides that any
person who is a director or officer of the Registrant shall be indemnified by
the Registrant to the fullest extent permitted from time to time by applicable
law. In addition, the By-laws provide that each person who was or is made a
party or is threatened to be made a party to or is involved in any threatened,
pending or completed action, suit or proceeding, whether civil, criminal,
administrative or investigative, by reason of the fact that he or she or a
person of whom he or she is the legal representative is or was a director or
officer of the Registrant or a director or elected officer of a corporation a
majority of the capital stock (other than directors' qualifying shares) of which
is owned directly or indirectly by the Registrant (a "Subsidiary") shall be
indemnified by the Registrant to the fullest extent permitted by applicable law.
The right to indemnification under the By-laws includes the right to be paid the
expenses incurred in defending a proceeding in advance of its final disposition
upon receipt (unless the Registrant upon authorization of the Board of Directors
waives said requirement to the extent permitted by applicable law) of an
undertaking by or on behalf of such person to repay such amount if it shall
ultimately be determined that such person is not entitled to be indemnified by
the Registrant.

                  The Registrant's By-laws also provide that the Registrant may,
to the extent authorized from time to time by the Board of Directors, provide
rights to indemnification, and rights to be paid by the Registrant the expenses
incurred in defending any proceeding in advance of its final disposition, to any
person who is or was an employee or agent (other than a director or officer) of
the Registrant or a Subsidiary and to any person who is or was serving at the
request of the Registrant or a Subsidiary as a director, officer, partner,
member, employee or agent of another corporation, partnership, limited liability
company, joint venture, trust or other enterprise at the request of the
Registrant or a Subsidiary, to the same extent as the By-laws provide with
respect to indemnification of, and advancement of expenses for, directors and
officers of the Registrant.

                  Under the By-laws, the Registrant has the power to purchase
and maintain insurance on behalf of any person who is or was a director,
officer, partner, member, employee or agent of the Registrant or of its
subsidiary, or of another corporation, partnership, limited liability company,
joint venture, trust or other enterprise, against any expense, liability or loss
whether or not the Registrant or its subsidiary would have the power to
indemnify that person against that expense, liability or loss under the
provisions of applicable law.
5

                  The Registrant has in effect insurance policies in the amount
of $125 million for general officers' and directors' liability insurance and $25
million for fiduciary liability insurance covering all of our directors and
officers in some of the instances where by law they may not be indemnified by
the Registrant.

Item 7.           Exemption from Registration Claimed.

                  Not applicable.

Item 8.           Exhibits.

                  The following exhibits are filed as part of this Registration
                  Statement:

                  4.1               Form of Trust Deed and Rules of the Morgan
                                    Stanley Dean Witter -- Cabot Aircraft
                                    Services Profit Sharing Plan.

                  4.2               Amended and Restated Certificate of
                                    Incorporation. Filed as Exhibit 3.1 to the
                                    Registrant's Annual Report on Form 10-K for
                                    the fiscal year ended November 30, 1998 and
                                    incorporated herein by reference.

                  4.3               Certificate of Elimination of the 7.80%
                                    Cumulative Preferred Stock ($200.00 Stated
                                    Value) of the Registrant. File as Exhibit
                                    3.2 to the Registrant's Quarterly Report on
                                    Form 10-Q for the quarter ended February 28,
                                    1999 and incorporated herein by reference.

                  4.4               Certificate of Elimination of the 7.82%
                                    Cumulative Preferred Stock ($200.00 Stated
                                    Value) of the Registrant. Filed as Exhibit
                                    3.3 to the Registrant's Quarterly Report on
                                    Form 10-Q for the quarter ended February 28,
                                    1999 and incorporated herein by
                                    reference.

                  4.5               By-Laws, as amended to date. Filed as
                                    Exhibit 3.4 to the Registrant's Quarterly
                                    Report on Form 10-Q for the quarter ended
                                    February 28, 1999 and incorporated herein by
                                    reference.

                  4.6               Rights Agreement dated as of April 25, 1995
                                    between the Registrant and Chemical Bank, as
                                    rights agent, which includes as Exhibit B
                                    thereto the Form of Rights Certificate.
                                    Filed as Exhibit 1 to the Registrant's
                                    Registration Statement on Form 8-A dated
                                    April 26, 1995 and incorporated herein by
                                    reference.

                  4.7               Amendment dated as of February 4, 1997 to
                                    the Rights Agreement between the Registrant
                                    and The Chase Manhattan Bank (as
6

                                    successor to Chemical Bank), as rights
                                    agent. Filed as Exhibit 4.1 to the
                                    Registrant's Current Report on Form 8-K
                                    dated February 4, 1997 and incorporated
                                    herein by reference.

                  4.8               Second Amendment, dated as of June 15, 1999,
                                    to the Rights Agreement dated as of April
                                    25, 1995, between Morgan Stanley Dean Witter
                                    & Co. (formerly Dean Witter, Discover & Co.)
                                    and Chase Manhattan Bank (formerly Chemical
                                    Bank), as rights agent Filed as Exhibit 4.3
                                    to the Registrant's Registration Statement
                                    on Form 8A/A dated June 29, 1999 and
                                    incorporated herein by reference.

                  15.1              Letter of Awareness from Deloitte & Touche
                                    LLP.

                  23.1              Consent of Deloitte & Touche LLP.

                  23.2              Consent of Ernst & Young LLP.

                  24.1              Powers of Attorney (included on signature
                                    page).

The shares of Common Stock registered hereby are not original issuance
securities. Pursuant to Item 8(a) of Part II of Form S-8, an opinion of counsel
as to the legality of the shares accordingly is not required.

Item 9.           Undertakings.

                  (a) The undersigned Registrant hereby undertakes;

                  (1) To file, during any period in which offers or sales
         are being made, a post-effective amendment to this registration
         statement:

                           (i) to include any prospectus required by Section
                  10(a)(3) of the Securities Act of 1933;

                           (ii) to reflect in the prospectus any facts or events
                  arising after the effective date of the registration statement
                  (or the most recent post-effective amendment thereof) which,
                  individually or in aggregate, represent a fundamental change
                  in the information set forth in this Registration Statement;
                  and

                           (iii) to include any material information with
                  respect to the plan of distribution not previously disclosed
                  in this Registration Statement or any material change to such
                  information in the Registration Statement;
7

         provided, however, that the undertakings set forth in paragraphs (1)(i)
         and (1)(ii) above do not apply if the information required to be
         included in a post-effective amendment by those paragraphs is contained
         in periodic reports filed by the Registrant pursuant to Section 13 or
         Section 15(d) of the Securities Exchange Act of 1934 that are
         incorporated by reference in this Registration Statement;

                  (2) That, for the purpose of determining any liability
         under the Securities Act of 1933, each such post-effective amendment
         shall be deemed to be a new registration statement relating to the
         securities offered therein, and the offering of such securities at that
         time shall be deemed to be the initial bona fide offering thereof; and

                  (3) To remove from registration by means of a
         post-effective amendment any of the securities being registered which
         remain unsold at the termination of the offering.

                  (b) The undersigned Registrant hereby further
undertakes that, for purposes of determining any liability under the Securities
Act of 1933, each filing of the Registrant's annual report pursuant to Section
13(a) or Section 15(d) of the Securities Exchange Act of 1934 (and, where
applicable, each filing of an employee benefit plan's annual report pursuant to
Section 15(d) of the Securities Exchange Act of 1934) that is incorporated by
reference in this Registration Statement shall be deemed to be a new
registration statement relating to the securities offered therein, and the
offering of such securities at the time shall be deemed to be the initial bona
fide offering thereof.

                  (c) Insofar as indemnification for liabilities arising
under the Securities Act of 1933 may be permitted to directors, officers and
controlling persons of the Registrant pursuant to the foregoing provisions, or
otherwise, the Registrant has been advised that in the opinion of the Securities
and Exchange Commission such indemnification is against public policy as
expressed in the Securities Act of 1933 and is, therefore, unenforceable. In the
event that a claim for indemnification against such liabilities (other than the
payment by the Registrant of expenses incurred or paid by a director, officer or
controlling person of the Registrant in the successful defense of any action,
suit or proceeding) is asserted by such director, officer or controlling person
in connection with the securities being registered, the Registrant will, unless
in the opinion of its counsel the matter has been settled by controlling
precedent, submit to a court of appropriate jurisdiction the question whether
such indemnification by it is against public policy as expressed in the
Securities Act of 1933 and will be governed by the final adjudication of such
issue.
8

                                   SIGNATURES

                  Pursuant to the requirements of the Securities Act of 1933, as
amended, the Registrant certifies that it has reasonable grounds to believe that
it meets all of the requirements for filing on Form S-8 and has duly caused this
Registration Statement to be signed on its behalf by the undersigned, thereunto
duly authorized, in the City of New York, State of New York on the 24th day of
January, 2000.

                                    MORGAN STANLEY DEAN WITTER & CO.
                                    (Registrant)

                                    By:  /s/ Phillip J. Purcell
                                    -------------------------------------
                                    Philip J. Purcell
                                    Chairman of the Board and
                                    Chief Executive Officer
9

                                POWER OF ATTORNEY

                  KNOW ALL PERSONS BY THESE PRESENTS that each person whose
signature appears below hereby constitutes and appoints Robert G. Scott, Ronald
T. Carman, Donald G. Kempf Jr., Ralph L. Pellecchio, Martin M. Cohen and William
J. O'Shaughnessy, Jr. and each of them singly, his or her true and lawful
attorney-in-fact and agent with full power of substitution and resubstitution,
for him or her and in his or her name, place and stead, in any and all
capacities, to sign any and all amendments, including post-effective amendments,
to this Registration Statement (any of which amendments may make such changes
and additions to this Registration Statement as such attorneys-in-fact may deem
necessary or appropriate) and to file the same, with all exhibits thereto, and
any other documents that may be required in connection therewith, granting unto
said attorneys-in-fact and agents full power and authority to be done in and
about the premises, as fully to all intents and purposes as he or she might or
could do in person, hereby ratifying and confirming all that said
attorneys-in-fact and agents, or their substitutes, may lawfully do or cause to
be done by virtue hereof.

                  Pursuant to the requirements of the Securities Act of 1933, as
amended, this Registration Statement has been signed by the following persons in
the capacities indicated on the 24th day of January, 2000.

       SIGNATURE                                TITLE

                                       Chairman of the Board and
/s/ Philip J. Purcell                  Chief Executive Officer
------------------------
Philip J. Purcell

                                       President, Chief Operating
/s/ John J. Mack                       Officer and Director
------------------------
John J. Mack

                                       Executive Vice President and Chief
/s/ Robert G. Scott                    Financial Officer (Principal Financial
------------------------               Officer)
Robert G. Scott

                                       Controller (Principal Accounting Officer)
/s/ Joanne Pace
------------------------
Joanne Pace

/s/ Robert P. Bauman                   Director
------------------------
Robert P. Bauman

/s/ Edward A. Brennan                  Director
------------------------
Edward A. Brennan
10

/s/ Diana D. Brooks                     Director
------------------------
Diana D. Brooks

/s/ Daniel B. Burke                     Director
------------------------
Daniel B. Burke

------------------------                Director
C. Robert Kidder

/s/ Charles F. Knight                   Director
------------------------
Charles F. Knight

/s/ Miles L. Marsh                      Director
------------------------
Miles L. Marsh

/s/ Michael A. Miles                    Director
------------------------
Michael A. Miles

/s/ Allen E. Murray                     Director
------------------------
Allen E. Murray

/s/ Clarence B. Rogers, Jr.             Director
------------------------
Clarence B. Rogers, Jr.

/s/ Laura D'Andrea Tyson                Director
------------------------
Laura D'Andrea Tyson
11

                                  Exhibit Index

         Exhibit No.                   Description of Document

         *4.1              Form of Trust Deed and Rules of the Morgan Stanley
                           Dean Witter -- Cabot Aircraft Services Profit Sharing
                           Plan.

         4.2               Amended and Restated Certificate of Incorporation.
                           Filed as Exhibit 3.1 to the Registrant's Annual
                           Report on Form 10-K for the fiscal year ended
                           November 30, 1998 and incorporated herein by
                           reference.

         4.3               Certificate of Elimination of the 7.80% Cumulative
                           Preferred Stock ($200.00 Stated Value) of the
                           Registrant. File as Exhibit 3.2 to the Registrant's
                           Quarterly Report on Form 10-Q for the quarter ended
                           February 28, 1999 and incorporated herein by
                           reference.

         4.4               Certificate of Elimination of the 7.82% Cumulative
                           Preferred Stock ($200.00 Stated Value) of the
                           Registrant. Filed as Exhibit 3.3 to the Registrant's
                           Quarterly Report on Form 10-Q for the quarter ended
                           February 28, 1999 and incorporated herein by
                           reference.

         4.5               By-Laws, as amended to date. Filed as Exhibit 3.4 to
                           the Registrant's Quarterly Report on Form 10-Q for
                           the quarter ended February 28, 1999 and incorporated
                           herein by reference.

         4.6               Rights Agreement dated as of April 25, 1995 between
                           the Registrant and Chemical Bank, as rights agent,
                           which includes as Exhibit B thereto the Form of
                           Rights Certificate. Filed as Exhibit 1 to the
                           Registrant's Registration Statement on Form 8-A dated
                           April 26, 1995 and incorporated herein by reference.

         4.7               Amendment dated as of February 4, 1997 to the Rights
                           Agreement between the Registrant and The Chase
                           Manhattan Bank (as successor to Chemical Bank), as
                           rights agent. Filed as Exhibit 4.1 to the
                           Registrant's Current Report on Form 8-K dated
                           February 4, 1997 and incorporated herein by
                           reference.

         4.8               Second Amendment, dated as of June 15, 1999, to the
                           Rights Agreement dated as of April 25, 1995, between
                           Morgan Stanley Dean Witter & Co. (formerly Dean
                           Witter, Discover & Co.) and Chase Manhattan Bank
                           (formerly Chemical Bank), as rights agent Filed as
                           Exhibit 4.3 to the Registrant's Registration
                           Statement on Form 8A/A dated June 29, 1999 and
                           incorporated herein by reference.
12

         *15.1             Letter of Awareness from Deloitte & Touche LLP.

         *23.1             Consent of Deloitte & Touche LLP.

         *23.2             Consent of Ernst & Young LLP.

         *24.1             Powers of Attorney (included on signature page).

--------------------
*    Filed Herewith