
<PAGE>
 
                      SECURITIES AND EXCHANGE COMMISSION

                            Washington, D.C. 20549

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


                                   FORM 8-K

                                CURRENT REPORT

                    Pursuant to Section 13 or 15(d) of the
                        Securities Exchange Act of 1934

      Date of Report (Date of earliest event reported):  February 28, 1997

                          Dean Witter, Discover & Co.
                          ---------------------------
                    (Exact name of Registrant as specified
                                in its charter)


          Delaware                1-11758                 36-3145972
   -------------------------------------------------------------------------
         (state or other        (Commission            (I.R.S. Employer
         jurisdiction of        File Number)          Identification No.)
         incorporation)


               Two World Trade Center, New York, New York 10048
               ------------------------------------------------
              (Address of principal executive offices)(Zip Code)

      Registrant's telephone number, including area code: (212) 392-2222
                                                          --------------


   -------------------------------------------------------------------------
                (Former address, if changed since last report.)


<PAGE>
 
Item 5.  OTHER EVENTS

As previously disclosed in Dean Witter, Discover & Co.'s ("DWD") current report
on Form 8-K dated February 4, 1997, DWD and Morgan Stanley Group Inc. ("Morgan
Stanley") announced a definitive agreement to merge ("the Merger"). This
transaction is intended to be accounted for as a pooling of interests and the
new company will be named Morgan Stanley, Dean Witter, Discover & Co. Under the
terms of the definitive agreement each of Morgan Stanley's common shares will be
exchanged for 1.65 of DWD's common shares. The Merger, which is expected to be
completed in mid-1997, is subject to customary closing conditions, including
certain regulatory approvals and the approval of the stockholders of both
companies.

Certain financial information for Morgan Stanley and unaudited pro forma
combined financial information for the combined entity giving effect to the
merger is set forth under Item 7(c) below as Exhibits 99.1, and 99.2.
respectively.

Attached and incorporated herein by reference as Exhibit 23.1 is a copy of the
consent of Ernst & Young LLP.

Item 7(c).  FINANCIAL STATEMENTS, PRO FORMA FINANCIAL STATEMENTS AND
EXHIBITS.
 
Exhibit No.    Description
- -------------  -----------

23.1           Consent of Ernst & Young LLP

99.1           The audited consolidated statement of financial condition of
               Morgan Stanley as of November 30, 1996 and November 30, 1995 and
               the related consolidated statements of income, cash flows and
               changes in shareholders' equity for each of the years in the
               three year period ended November 30, 1996.

99.2           The Morgan Stanley, Dean Witter, Discover & Co. unaudited pro 
               forma condensed combined statement of financial condition at
               December 31, 1996, and unaudited pro forma condensed combined
               statements of income for the twelve months ended December 31,
               1996, 1995 and 1994.
<PAGE>
 

                                   SIGNATURE

        Pursuant to the requirements of the Securities Exchange Act of 1934, the
registrant has duly caused this report to be signed on its behalf by the 
undersigned, thereto duly authorized.


                                        DEAN WITTER, DISCOVER & CO.
                                        -----------------------------------
                                                (Registrant)

                                        By: /s/ Ronald T. Carman
                                        -----------------------------------
                                            Ronald T. Carman
                                            Senior Vice President


Dated:  February 28, 1997


<PAGE>
 
                      SECURITIES AND EXCHANGE COMMISSION
                            WASHINGTON, D.C. 20549





                          DEAN WITTER, DISCOVER & CO.





                                   EXHIBITS
                             TO CURRENT REPORT ON
                        FORM 8-K DATED FEBRUARY 28, 1997




                                                  Commission File Number 1-11758
<PAGE>
 
 
Exhibit No.    Description
- -------------  -----------

23.1           Consent of Ernst & Young LLP

99.1           The audited consolidated statement of financial condition of
               Morgan Stanley as of November 30, 1996 and November 30, 1995 and
               the related consolidated statements of income, cash flows and
               changes in shareholders' equity for each of the years in the
               three year period ended November 30, 1996.

99.2           The Morgan Stanley, Dean Witter, Discover & Co. unaudited pro 
               forma condensed combined statement of financial condition at
               December 31, 1996, and unaudited pro forma condensed combined
               statements of income for the twelve months ended December 31,
               1996, 1995 and 1994.
