Washington, D.C. 20549


                                                 FORM 8-K

                                              CURRENT REPORT

                                 PURSUANT TO SECTION 13 OR 15(d) OF THE
                                     SECURITIES EXCHANGE ACT OF 1934

                                              April 21, 2004
                                    (Date of earliest event reported)

                                     Marsh & McLennan Companies, Inc.
                          (Exact name of registrant as specified in its charter)

              Delaware                            1-5998                           36-2668272
  (State or other jurisdiction           (Commission File Number)                (IRS Employer
        of incorporation)                                                      Identification No.)

1166 Avenue of the Americas, New York, NY                                            10036
(Address of principal executive offices)                                           (Zip Code)

                                               (212) 345-5000
                            (Registrant's telephone number, including area code)

Item 7.   Financial Statements and Exhibits.

          (a)   None.

          (b)   None.

          (c)   Exhibits

                 99.1   Press Release dated April 21, 2004.

Item 12.   Results of Operations and Financial Condition.

           On April 21, 2004, Marsh & McLennan Companies, Inc. issued a press
release announcing its unaudited first quarter financial results for the
quarter ended March 31, 2004.  A copy of the press release is attached to this
Report as an exhibit and is incorporated herein by reference.


         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 hereunto duly authorized.

                                               MARSH & McLENNAN COMPANIES, INC.

                                               By:  /s/ Leon J. Lichter
                                                    Name:   Leon J. Lichter
                                                    Title:  Vice President &
                                                             Corporate Secretary

Date:  April 21, 2004

Exhibit Index

Exhibit (99.1):  Press release dated April 21, 2004.