As filed with the Securities and Exchange Commission on September 3, 1998
                                         Registration Statement 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           (IRS Employer Identification Number)
incorporation or organization)

                                 1585 Broadway
                           New York, New York 10036
                           ------------------------
         (Address of principal executive offices, including zip code)

       DEAN WITTER START PLAN (SAVING TODAY AFFORDS RETIREMENT TOMORROW)
                           (Full title of the plan)

                             Christine A. Edwards
          Executive Vice President, Chief Legal Officer and Secretary
                       Morgan Stanley Dean Witter & Co.
                                 1585 Broadway
                           New York, New York 10036
                                (212) 761-4000
           (Name, address and telephone number of agent for service)

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

                        Calculation of Registration Fee
<TABLE>
<CAPTION>
--------------------------------------------------------------------------------------------------------------------------
                                                        Proposed Maximum         Proposed Maximum          Amount of
  Title of Securities to be       Amount to be         Offering Price Per       Aggregate Offering       Registration
          Registered              Registered(1)             Share(2)                   Price                  Fee
--------------------------------------------------------------------------------------------------------------------------
<S>                               <C>                       <C>                   <C>                    <C>
 Common Stock, par                 5,000,000                 $54.00                $270,000,000           $79,650.00
value $.01 per share(3)(4)          shares
--------------------------------------------------------------------------------------------------------------------------
</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) Estimated  pursuant to Rule 457(h) solely for purposes of calculating  the
amount of the  registration  fee based  upon the  average  of the high and low
prices reported for the shares on the New York Stock  Exchange on September 1,
1998.

(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,  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.

(4) In  addition,  pursuant to Rule 416(c) under the  Securities  Act of 1933,
this Registration  Statement also covers an indeterminate  amount of interests
to be offered or sold pursuant to the employee benefit plan described herein.

<PAGE>

                                    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 2 of  this  form  taken
together  constitute a prospectus that meets the requirements of Section 10(a)
of the Securities Act of 1933.

                                    PART II
              INFORMATION REQUIRED IN THE REGISTRATION STATEMENT

Item 3.  Incorporation of Documents by Reference.
         ----------------------------------------

The  Registrant  hereby   incorporates  the  following   documents  herein  by
reference:

(a) the  Registrant's  Annual  Report on Form 10-K for the  fiscal  year ended
November 30, 1997;

(b) the  Registrant's  Quarterly  Reports on Form 10-Q for the quarters  ended
February  28, 1998 (as amended by Form 10-Q/A  (Amendment  No. 1) filed May 6,
1998) and May 31, 1998;

(c) the  Registrant's  Current  Reports  on Form 8-K dated  December  8, 1997,
January 7,  1998,  February  12,  1998,  March  26,  1998,  June 18, 1998  and 
September 1, 1998;

(d)  the  description  of  the  Registrant's  Common  Stock  contained  in the
Registrant's  Registration  Statement  on Form 10 filed  with  the  Commission
pursuant to Section 12 of the Securities Exchange Act of 1934, as amended (the
"Exchange Act"), 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 Plan contained in
the Registrant's  Registration Statement on Form 8-A filed with the Commission
pursuant to Section 12 of the Exchange  Act on April 26,  1995,  as amended by
the Form 8-A/A dated May 4, 1995; and

(f) Amendment,  dated February 4, 1997, to the Rights  Agreement,  dated as of
April 25, 1995,  between the Registrant and The Chase Manhattan Bank (formerly
Chemical Bank), as Rights Agent  (incorporated  by reference to Exhibit 4.1 to
the Registrant's Current Report on Form 8-K dated February 4, 1997).

All documents  subsequently filed by the Registrant pursuant to Section 13(a),
Section  13(c),  Section 14 and  Section 15 of the  Exchange  Act prior to the
filing of a  post-effective  amendment  to this  Registration  Statement  that
indicates that all securities  offered have been sold or which deregisters all
securities  then  remaining  unsold,  shall be deemed  incorporated  herein by
reference 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 required.

<PAGE>

Item 5.  Interests of Named Experts and Counsel.
         ---------------------------------------

         No material interests.

Item 6.  Indemnification of Directors and Officers.
         ------------------------------------------

         Article VIII of the Amended and Restated Certificate of Incorporation
of the  Company  ("Certificate  of  Incorporation")  and  Section  6.07 of the
Amended and Restated  By-Laws of the Company  ("By-Laws"),  each as amended to
date, provide for the indemnification of the Company's directors and officers.
The Certificate of Incorporation provides that any person who is a director or
officer of the  Company  shall be  indemnified  by the  Company 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  Company 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 Company (a "Subsidiary") shall be indemnified by the Company
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 connection with any proceeding in advance of its final disposition
upon receipt (unless the Company 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 Company.

         The  Company's  By-Laws  also  provide  that the Company  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 Company 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
Company or a Subsidiary and to any person who is or was serving at the request
of the  Company 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
Company  or a  Subsidiary,  to the same  scope  and  effect  as the  foregoing
indemnification of directors and officers of the Company.

         Under the By-Laws, the Company 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  Company  or  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
Company or a  Subsidiary  would have the power to  indemnify  him against such
expense, liability or loss under the provisions of applicable law.

         The  Company 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 the  Company's
directors  and  officers  in  certain  instances  where by law they may not be
indemnified by the Company.

Item 7.  Exemption From Registration Claimed.
         ------------------------------------

         Not applicable.

Item 8.  Exhibits.
         ---------

4.1      Dean Witter START Plan (Savings  Today Affords  Retirement  Tomorrow)
         (amended and  restated as of January 1, 1997).  Filed as Exhibit 10.9
         to the  Registrant's  Annual  Report on Form 10-K for the year  ended
         December 31, 1996 and incorporated herein by reference.
4.2      Amendment to Dean Witter START Plan  (Saving Today Affords Retirement
         Tomorrow) (adopted December 10, 1997).  Filed as Exhibit 10.11 to the
         Registrant's  Annual  Report on Form 10-K for the  fiscal  year ended
         November 30, 1997 and incorporated herein by reference.
4.3      Amendments to Dean Witter START Plan (Saving Today Affords Retirement
         Tomorrow)  (effective  May 31,  1997).  Filed as Exhibit  10.2 to the
         Registrant's  Quarterly Report on Form 10-Q for the quarter ended May
         31, 1998 and incorporated herein by reference.
4.4      Amendment to Dean Witter START Plan (Saving Today Affords  Retirement
         Tomorrow) (adopted April 14, 1998,  effective as of January 1, 1998).
         Filed as Exhibit 10.3 to the  Registrant's  Quarterly  Report on Form
         10-Q for the quarter  ended May 31, 1998 and  incorporated  herein by
         reference.
4.5      Amended and Restated  Certificate of Incorporation.  Filed as Exhibit
         3.1 to the Registrant's Current Report on Form 8-K dated May 31, 1997
         and incorporated herein by reference.
4.6      Certificate  of  Designation  of  the  Registrant   relating  to  the
         Registrant's Series A Junior Participating  Preferred Stock. Filed as
         Exhibit 3(b) to the Registrant's  Registration Statement No. 33-92172
         on Form S-3 and incorporated herein by reference.
4.7      Certificate  of  Amendment  to Amended and  Restated  Certificate  of
         Incorporation  of the Registrant as filed with the Secretary of State
         of the State of Delaware on March 24,  1998.  Filed as Exhibit 3.2 to
         the Registrant's  Quarterly Report on Form 10-Q for the quarter ended
         February 28, 1998 and incorporated herein by reference.
4.8      By-Laws, as amended to date. Filed as Exhibit 3.3 to the Registrant's
         Quarterly Report on Form 10-Q for the quarter ended February 28, 1998
         and incorporated herein by reference.
4.9      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 by reference herein.
4.10     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.
5.1      Opinion  of Brown & Wood LLP.
15.1     Letter  of  awareness from Deloitte & Touche LLP concerning unaudited
         interim financial information.
15.2     Letter  of  awareness  from  Ernst & Young LLP  concerning  unaudited
         interim financial information.
23.1     Consent of Deloitte & Touche LLP.
23.2     Consent of Ernst & Young LLP.
23.3     Consent of Brown & Wood LLP (included as part of Exhibit  5.1). 
24.1     Powers of Attorney (included in Part II of the Registration Statement
         under the caption "Signatures").

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  the  aggregate,   represent  a  fundamental   change  in  the
         information set forth in the Registration Statement.  Notwithstanding
         the  foregoing,  any increase or decrease in the volume of securities
         offered (if the total dollar value of  securities  offered  would not
         exceed that which was  registered) and any deviation from the high or
         low end of the estimated  maximum  offering range may be reflected in
         the form of a prospectus  filed with the Commission  pursuant to Rule
         424(b)  if,  in the  aggregate,  the  changes  in  volume  and  price
         represent no more than a 20% change in the maximum aggregate offering
         price set forth in the "Calculation of Registration Fee" table in the
         effective registration statement; and

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

         provided, however, that paragraphs (a)(1)(i) and (ii) 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 the 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  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 the
Registration  Statement  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.

(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
Act  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  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 Act
and will be governed by a final adjudication of such issue.

<PAGE>

                                  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 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 New  York,  New  York,  on  this  3rd  day of
September, 1998.

                            MORGAN STANLEY DEAN WITTER & CO.

                            By:  /s/  Philip J. Purcell
                                 ------------------------------------
                            Name:     Philip J. Purcell
                            Title     Chairman of the Board, Chief Executive
                                             Officer and Director

                               POWER OF ATTORNEY

         KNOW ALL PERSONS BY THESE  PRESENTS that each person whose  signature
appears below hereby constitutes and appoints Christine A. Edwards,  Robert G.
Scott,  Ronald T. Carman,  Ralph L. Pellecchio,  William J.  O'Shaughnessy and
Martin  M.  Cohen  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 below by the following
persons in the capacities indicated on this 3rd day of September, 1998.

       Signature                                   Title

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

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

/s/  Thomas C. Schneider            Executive Vice President and Director
----------------------------
     Thomas C. Schneider

/s/  Richard B. Fisher           Chairman of Executive Committee of Board of
----------------------------               Directors and Director
     Richard B. Fisher      

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

/s/  Eileen K. Murray                              Controller
----------------------------             (Principal Accounting Officer)
     Eileen K. Murray       

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

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

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

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

/s/  C. Robert Kidder                               Director
----------------------------
     C. Robert Kidder

/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>

The Plan.  Pursuant to the  requirements  of the  Securities  Act of 1933,  as
amended, the administrator of the Dean Witter START Plan (Saving Today Affords
Retirement Tomorrow) has duly caused this Registration  Statement to be signed
on the Plan's behalf by the  undersigned,  thereunto duly  authorized,  in the
City of New York and State of New York, on this 3rd day of September, 1998.

                             Dean Witter  START Plan (Saving  Today
                             Affords Retirement Tomorrow)

                             By:   Dean Witter Reynolds Inc.,
                                   Plan Administrator


                             By:   /s/  Michael T. Cunningham
                                   -------------------------------
                                   Name:   Michael T. Cunningham
                                   Title:  Senior Vice President

<PAGE>

                                 EXHIBIT INDEX

Exhibit
Number
-------

4.1      Dean Witter START Plan (Savings  Today Affords  Retirement  Tomorrow)
         (amended and  restated as of January 1, 1997).  Filed as Exhibit 10.9
         to the  Registrant's  Annual  Report on Form 10-K for the year  ended
         December 31, 1996 and incorporated herein by reference.
4.2      Amendment to Dean Witter START Plan  (Saving Today Affords Retirement
         Tomorrow) (adopted December 10, 1997).  Filed as Exhibit 10.11 to the
         Registrant's  Annual  Report on Form 10-K for the  fiscal  year ended
         November 30, 1997 and incorporated herein by reference.
4.3      Amendments to Dean Witter START Plan (Saving Today Affords Retirement
         Tomorrow)  (effective  May 31,  1997).  Filed as Exhibit  10.2 to the
         Registrant's  Quarterly Report on Form 10-Q for the quarter ended May
         31, 1998 and incorporated herein by reference.
4.4      Amendment to Dean Witter START Plan (Saving Today Affords  Retirement
         Tomorrow) (adopted April 14, 1998,  effective as of January 1, 1998).
         Filed as Exhibit 10.3 to the  Registrant's  Quarterly  Report on Form
         10-Q for the quarter  ended May 31, 1998 and  incorporated  herein by
         reference.
4.5      Amended and Restated  Certificate of Incorporation.  Filed as Exhibit
         3.1 to the Registrant's Current Report on Form 8-K dated May 31, 1997
         and incorporated herein by reference.
4.6      Certificate  of  Designation  of  the  Registrant   relating  to  the
         Registrant's Series A Junior Participating  Preferred Stock. Filed as
         Exhibit 3(b) to the Registrant's  Registration Statement No. 33-92172
         on Form S-3 and incorporated herein by reference.
4.7      Certificate  of  Amendment  to Amended and  Restated  Certificate  of
         Incorporation  of the Registrant as filed with the Secretary of State
         of the State of Delaware on March 24,  1998.  Filed as Exhibit 3.2 to
         the Registrant's  Quarterly Report on Form 10-Q for the quarter ended
         February 28, 1998 and incorporated herein by reference.
4.8      By-Laws, as amended to date. Filed as Exhibit 3.3 to the Registrant's
         Quarterly Report on Form 10-Q for the quarter ended February 28, 1998
         and incorporated herein by reference.
4.9      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 by reference herein.
4.10     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.
5.1      Opinion of Brown & Wood LLP.
15.1     Letter of awareness from Deloitte & Touche LLP  concerning  unaudited
         interim financial information.
15.2     Letter  of  awareness  from  Ernst & Young LLP  concerning  unaudited
         interim financial information.
23.1     Consent of Deloitte & Touche LLP.
23.2     Consent of Ernst & Young LLP.
23.3     Consent of Brown & Wood LLP (included as part of Exhibit 5.1).
24.1     Powers of Attorney (included in Part II of the Registration Statement
         under the caption "Signatures").
[{"type": "S-8", "sequence": "1", "description": "T:\\EDGAR\\324886", "secsgml_size_bytes": 28645}]
{"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": "333-62869", "film-number": "98704069"}, "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 September 3, 1998
                                         Registration Statement 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           (IRS Employer Identification Number)
incorporation or organization)

                                 1585 Broadway
                           New York, New York 10036
                           ------------------------
         (Address of principal executive offices, including zip code)

       DEAN WITTER START PLAN (SAVING TODAY AFFORDS RETIREMENT TOMORROW)
                           (Full title of the plan)

                             Christine A. Edwards
          Executive Vice President, Chief Legal Officer and Secretary
                       Morgan Stanley Dean Witter & Co.
                                 1585 Broadway
                           New York, New York 10036
                                (212) 761-4000
           (Name, address and telephone number of agent for service)

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

                        Calculation of Registration Fee
--------------------------------------------------------------------------------------------------------------------------
                                                        Proposed Maximum         Proposed Maximum          Amount of
  Title of Securities to be       Amount to be         Offering Price Per       Aggregate Offering       Registration
          Registered              Registered(1)             Share(2)                   Price                  Fee
--------------------------------------------------------------------------------------------------------------------------
Common Stock, par                 5,000,000                 $54.00                $270,000,000           $79,650.00
value $.01 per share(3)(4)          shares
--------------------------------------------------------------------------------------------------------------------------
(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) Estimated  pursuant to Rule 457(h) solely for purposes of calculating  the
amount of the  registration  fee based  upon the  average  of the high and low
prices reported for the shares on the New York Stock  Exchange on September 1,
1998.

(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,  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.

(4) In  addition,  pursuant to Rule 416(c) under the  Securities  Act of 1933,
this Registration  Statement also covers an indeterminate  amount of interests
to be offered or sold pursuant to the employee benefit plan described herein.
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 2 of  this  form  taken
together  constitute a prospectus that meets the requirements of Section 10(a)
of the Securities Act of 1933.

                                    PART II
              INFORMATION REQUIRED IN THE REGISTRATION STATEMENT

Item 3.  Incorporation of Documents by Reference.
         ----------------------------------------

The  Registrant  hereby   incorporates  the  following   documents  herein  by
reference:

(a) the  Registrant's  Annual  Report on Form 10-K for the  fiscal  year ended
November 30, 1997;

(b) the  Registrant's  Quarterly  Reports on Form 10-Q for the quarters  ended
February  28, 1998 (as amended by Form 10-Q/A  (Amendment  No. 1) filed May 6,
1998) and May 31, 1998;

(c) the  Registrant's  Current  Reports  on Form 8-K dated  December  8, 1997,
January 7,  1998,  February  12,  1998,  March  26,  1998,  June 18, 1998  and 
September 1, 1998;

(d)  the  description  of  the  Registrant's  Common  Stock  contained  in the
Registrant's  Registration  Statement  on Form 10 filed  with  the  Commission
pursuant to Section 12 of the Securities Exchange Act of 1934, as amended (the
"Exchange Act"), 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 Plan contained in
the Registrant's  Registration Statement on Form 8-A filed with the Commission
pursuant to Section 12 of the Exchange  Act on April 26,  1995,  as amended by
the Form 8-A/A dated May 4, 1995; and

(f) Amendment,  dated February 4, 1997, to the Rights  Agreement,  dated as of
April 25, 1995,  between the Registrant and The Chase Manhattan Bank (formerly
Chemical Bank), as Rights Agent  (incorporated  by reference to Exhibit 4.1 to
the Registrant's Current Report on Form 8-K dated February 4, 1997).

All documents  subsequently filed by the Registrant pursuant to Section 13(a),
Section  13(c),  Section 14 and  Section 15 of the  Exchange  Act prior to the
filing of a  post-effective  amendment  to this  Registration  Statement  that
indicates that all securities  offered have been sold or which deregisters all
securities  then  remaining  unsold,  shall be deemed  incorporated  herein by
reference 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 required.
Item 5.  Interests of Named Experts and Counsel.
         ---------------------------------------

         No material interests.

Item 6.  Indemnification of Directors and Officers.
         ------------------------------------------

         Article VIII of the Amended and Restated Certificate of Incorporation
of the  Company  ("Certificate  of  Incorporation")  and  Section  6.07 of the
Amended and Restated  By-Laws of the Company  ("By-Laws"),  each as amended to
date, provide for the indemnification of the Company's directors and officers.
The Certificate of Incorporation provides that any person who is a director or
officer of the  Company  shall be  indemnified  by the  Company 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  Company 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 Company (a "Subsidiary") shall be indemnified by the Company
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 connection with any proceeding in advance of its final disposition
upon receipt (unless the Company 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 Company.

         The  Company's  By-Laws  also  provide  that the Company  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 Company 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
Company or a Subsidiary and to any person who is or was serving at the request
of the  Company 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
Company  or a  Subsidiary,  to the same  scope  and  effect  as the  foregoing
indemnification of directors and officers of the Company.

         Under the By-Laws, the Company 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  Company  or  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
Company or a  Subsidiary  would have the power to  indemnify  him against such
expense, liability or loss under the provisions of applicable law.

         The  Company 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 the  Company's
directors  and  officers  in  certain  instances  where by law they may not be
indemnified by the Company.

Item 7.  Exemption From Registration Claimed.
         ------------------------------------

         Not applicable.

Item 8.  Exhibits.
         ---------

4.1      Dean Witter START Plan (Savings  Today Affords  Retirement  Tomorrow)
         (amended and  restated as of January 1, 1997).  Filed as Exhibit 10.9
         to the  Registrant's  Annual  Report on Form 10-K for the year  ended
         December 31, 1996 and incorporated herein by reference.
4.2      Amendment to Dean Witter START Plan  (Saving Today Affords Retirement
         Tomorrow) (adopted December 10, 1997).  Filed as Exhibit 10.11 to the
         Registrant's  Annual  Report on Form 10-K for the  fiscal  year ended
         November 30, 1997 and incorporated herein by reference.
4.3      Amendments to Dean Witter START Plan (Saving Today Affords Retirement
         Tomorrow)  (effective  May 31,  1997).  Filed as Exhibit  10.2 to the
         Registrant's  Quarterly Report on Form 10-Q for the quarter ended May
         31, 1998 and incorporated herein by reference.
4.4      Amendment to Dean Witter START Plan (Saving Today Affords  Retirement
         Tomorrow) (adopted April 14, 1998,  effective as of January 1, 1998).
         Filed as Exhibit 10.3 to the  Registrant's  Quarterly  Report on Form
         10-Q for the quarter  ended May 31, 1998 and  incorporated  herein by
         reference.
4.5      Amended and Restated  Certificate of Incorporation.  Filed as Exhibit
         3.1 to the Registrant's Current Report on Form 8-K dated May 31, 1997
         and incorporated herein by reference.
4.6      Certificate  of  Designation  of  the  Registrant   relating  to  the
         Registrant's Series A Junior Participating  Preferred Stock. Filed as
         Exhibit 3(b) to the Registrant's  Registration Statement No. 33-92172
         on Form S-3 and incorporated herein by reference.
4.7      Certificate  of  Amendment  to Amended and  Restated  Certificate  of
         Incorporation  of the Registrant as filed with the Secretary of State
         of the State of Delaware on March 24,  1998.  Filed as Exhibit 3.2 to
         the Registrant's  Quarterly Report on Form 10-Q for the quarter ended
         February 28, 1998 and incorporated herein by reference.
4.8      By-Laws, as amended to date. Filed as Exhibit 3.3 to the Registrant's
         Quarterly Report on Form 10-Q for the quarter ended February 28, 1998
         and incorporated herein by reference.
4.9      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 by reference herein.
4.10     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.
5.1      Opinion  of Brown & Wood LLP.
15.1     Letter  of  awareness from Deloitte & Touche LLP concerning unaudited
         interim financial information.
15.2     Letter  of  awareness  from  Ernst & Young LLP  concerning  unaudited
         interim financial information.
23.1     Consent of Deloitte & Touche LLP.
23.2     Consent of Ernst & Young LLP.
23.3     Consent of Brown & Wood LLP (included as part of Exhibit  5.1). 
24.1     Powers of Attorney (included in Part II of the Registration Statement
         under the caption "Signatures").

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  the  aggregate,   represent  a  fundamental   change  in  the
         information set forth in the Registration Statement.  Notwithstanding
         the  foregoing,  any increase or decrease in the volume of securities
         offered (if the total dollar value of  securities  offered  would not
         exceed that which was  registered) and any deviation from the high or
         low end of the estimated  maximum  offering range may be reflected in
         the form of a prospectus  filed with the Commission  pursuant to Rule
         424(b)  if,  in the  aggregate,  the  changes  in  volume  and  price
         represent no more than a 20% change in the maximum aggregate offering
         price set forth in the "Calculation of Registration Fee" table in the
         effective registration statement; and

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

         provided, however, that paragraphs (a)(1)(i) and (ii) 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 the 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  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 the
Registration  Statement  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.

(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
Act  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  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 Act
and will be governed by a final adjudication of such issue.
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 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 New  York,  New  York,  on  this  3rd  day of
September, 1998.

                            MORGAN STANLEY DEAN WITTER & CO.

                            By:  /s/  Philip J. Purcell
                                 ------------------------------------
                            Name:     Philip J. Purcell
                            Title     Chairman of the Board, Chief Executive
                                             Officer and Director

                               POWER OF ATTORNEY

         KNOW ALL PERSONS BY THESE  PRESENTS that each person whose  signature
appears below hereby constitutes and appoints Christine A. Edwards,  Robert G.
Scott,  Ronald T. Carman,  Ralph L. Pellecchio,  William J.  O'Shaughnessy and
Martin  M.  Cohen  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 below by the following
persons in the capacities indicated on this 3rd day of September, 1998.

       Signature                                   Title

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

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

/s/  Thomas C. Schneider            Executive Vice President and Director
----------------------------
     Thomas C. Schneider

/s/  Richard B. Fisher           Chairman of Executive Committee of Board of
----------------------------               Directors and Director
     Richard B. Fisher      

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

/s/  Eileen K. Murray                              Controller
----------------------------             (Principal Accounting Officer)
     Eileen K. Murray       

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

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

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

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

/s/  C. Robert Kidder                               Director
----------------------------
     C. Robert Kidder

/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
The Plan.  Pursuant to the  requirements  of the  Securities  Act of 1933,  as
amended, the administrator of the Dean Witter START Plan (Saving Today Affords
Retirement Tomorrow) has duly caused this Registration  Statement to be signed
on the Plan's behalf by the  undersigned,  thereunto duly  authorized,  in the
City of New York and State of New York, on this 3rd day of September, 1998.

                             Dean Witter  START Plan (Saving  Today
                             Affords Retirement Tomorrow)

                             By:   Dean Witter Reynolds Inc.,
                                   Plan Administrator

                             By:   /s/  Michael T. Cunningham
                                   -------------------------------
                                   Name:   Michael T. Cunningham
                                   Title:  Senior Vice President
EXHIBIT INDEX

Exhibit
Number
-------

4.1      Dean Witter START Plan (Savings  Today Affords  Retirement  Tomorrow)
         (amended and  restated as of January 1, 1997).  Filed as Exhibit 10.9
         to the  Registrant's  Annual  Report on Form 10-K for the year  ended
         December 31, 1996 and incorporated herein by reference.
4.2      Amendment to Dean Witter START Plan  (Saving Today Affords Retirement
         Tomorrow) (adopted December 10, 1997).  Filed as Exhibit 10.11 to the
         Registrant's  Annual  Report on Form 10-K for the  fiscal  year ended
         November 30, 1997 and incorporated herein by reference.
4.3      Amendments to Dean Witter START Plan (Saving Today Affords Retirement
         Tomorrow)  (effective  May 31,  1997).  Filed as Exhibit  10.2 to the
         Registrant's  Quarterly Report on Form 10-Q for the quarter ended May
         31, 1998 and incorporated herein by reference.
4.4      Amendment to Dean Witter START Plan (Saving Today Affords  Retirement
         Tomorrow) (adopted April 14, 1998,  effective as of January 1, 1998).
         Filed as Exhibit 10.3 to the  Registrant's  Quarterly  Report on Form
         10-Q for the quarter  ended May 31, 1998 and  incorporated  herein by
         reference.
4.5      Amended and Restated  Certificate of Incorporation.  Filed as Exhibit
         3.1 to the Registrant's Current Report on Form 8-K dated May 31, 1997
         and incorporated herein by reference.
4.6      Certificate  of  Designation  of  the  Registrant   relating  to  the
         Registrant's Series A Junior Participating  Preferred Stock. Filed as
         Exhibit 3(b) to the Registrant's  Registration Statement No. 33-92172
         on Form S-3 and incorporated herein by reference.
4.7      Certificate  of  Amendment  to Amended and  Restated  Certificate  of
         Incorporation  of the Registrant as filed with the Secretary of State
         of the State of Delaware on March 24,  1998.  Filed as Exhibit 3.2 to
         the Registrant's  Quarterly Report on Form 10-Q for the quarter ended
         February 28, 1998 and incorporated herein by reference.
4.8      By-Laws, as amended to date. Filed as Exhibit 3.3 to the Registrant's
         Quarterly Report on Form 10-Q for the quarter ended February 28, 1998
         and incorporated herein by reference.
4.9      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 by reference herein.
4.10     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.
5.1      Opinion of Brown & Wood LLP.
15.1     Letter of awareness from Deloitte & Touche LLP  concerning  unaudited
         interim financial information.
15.2     Letter  of  awareness  from  Ernst & Young LLP  concerning  unaudited
         interim financial information.
23.1     Consent of Deloitte & Touche LLP.
23.2     Consent of Ernst & Young LLP.
23.3     Consent of Brown & Wood LLP (included as part of Exhibit 5.1).
24.1     Powers of Attorney (included in Part II of the Registration Statement
         under the caption "Signatures").