Exhibit 99.1350CERT

         Certification Pursuant to Section 906 of the Sarbanes Oxley Act

      I, Terry K. Glenn, President of CMA Massachusetts Municipal Money Fund of
      CMA Multi-State Municipal Series Trust (the "Fund"), certify that:

            1.    The N-CSR of the Fund (the "Report") fully complies with the
                  requirements of Section 13(a) or 15(d) of the Securities
                  Exchange Act of 1934; and

            2.    The information contained in the Report fairly presents, in
                  all material respects, the financial condition and results of
                  operations of the Fund.

      Dated: May 21, 2004


                                                /s/ Terry K. Glenn
                                                ------------------
                                                Terry K. Glenn,
                                                President of
                                                CMA Massachusetts Municipal
                                                Money Fund of CMA Multi-State
                                                Municipal Series Trust

      A signed original of this written statement required by Section 906, or
      other document authenticating, acknowledging, or otherwise adopting the
      signature that appears in typed form within the electronic version of this
      written statement required by Section 906, has been provided to CMA
      Massachusetts Municipal Money Fund of CMA Multi-State Municipal Series
      Trust and will be retained by CMA Massachusetts Municipal Money Fund of
      CMA Multi-State Municipal Series Trust and furnished to the Securities and
      Exchange Commission or its staff upon request.



Exhibit 99.1350CERT

         Certification Pursuant to Section 906 of the Sarbanes Oxley Act

      I, Donald C. Burke, Chief Financial Officer of CMA Massachusetts Municipal
      Money Fund of CMA Multi-State Municipal Series Trust (the "Fund"), certify
      that:

            1.    The N-CSR of the Fund (the "Report") fully complies with the
                  requirements of Section 13(a) or 15(d) of the Securities
                  Exchange Act of 1934; and

            2.    The information contained in the Report fairly presents, in
                  all material respects, the financial condition and results of
                  operations of the Fund.

      Dated: May 21, 2004


                                                /s/ Donald C. Burke
                                                -------------------
                                                Donald C. Burke,
                                                Chief Financial Officer of
                                                CMA Massachusetts Municipal
                                                Money Fund of CMA Multi-State
                                                Municipal Series Trust

      A signed original of this written statement required by Section 906, or
      other document authenticating, acknowledging, or otherwise adopting the
      signature that appears in typed form within the electronic version of this
      written statement required by Section 906, has been provided to CMA
      Massachusetts Municipal Money Fund of CMA Multi-State Municipal Series
      Trust and will be retained by CMA Massachusetts Municipal Money Fund of
      CMA Multi-State Municipal Series Trust and furnished to the Securities and
      Exchange Commission or its staff upon request.