UNITED STATES
                       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)         October 23, 2003
                                                 -------------------------------

                         Cass Information Systems, Inc.
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             (Exact Name of Registrant as Specified in its Charter)

                                    Missouri
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                 (State or Other Jurisdiction of Incorporation)

         2-80070                                           43-1265338
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(Commission File Number)                       (IRS Employer Identification No.)

13001 Hollenberg Drive, Bridgeton, Missouri                             63044
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  (Address of Principal Executive Offices)                            (Zip Code)

                                 (314) 506-5500
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              (Registrant's Telephone Number, Including Area Code)

                                       N/A
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          (Former Name or Former Address, if Changed Since Last Report)



                         CASS INFORMATION SYSTEMS, INC.

                                    FORM 8-K

Item 7. Financial Statements and Exhibits.

(c)   Exhibits

      Exhibit No.     Description
      -----------     -----------

          99.1        Press Release dated October 23, 2003, issued by Cass
                      Information Systems, Inc. (the Registrant)

Item 9. Information Furnished Under Item 12 - Results of Operations and
        Financial Condition

      The information in this report is furnished pursuant to Item 12,
"Disclosure of Results of Operations and Financial Condition."

      On October 23, 2003, the registrant issued a press release announcing its
preliminary results of operations for the quarter ended September 30, 2003. A
copy of the press release is attached hereto as Exhibit 99.1 and hereby
incorporated by reference. The information in this Form 8-K is being furnished
under Item 12 and shall not be deemed to be "filed" for the purposes of Section
18 of the Securities Exchange Act of 1934 (the "Exchange Act"), or otherwise
subject to the liabilities of such section, nor shall such information be deemed
incorporated by reference in any filing under the Securities Act of 1933 or the
Exchange Act, except as shall be expressly set forth by specific reference in
such a filing.


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                                   SIGNATURES

      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.

                                            Cass Information Systems, Inc.


October 23, 2003                    By:        /s/ Lawrence A. Collett
                                        ----------------------------------------
                                                  Lawrence A. Collett
                                          Chairman and Chief Executive Officer


October 23, 2003                    By:         /s/ Eric H. Brunngraber
                                        ----------------------------------------
                                                  Eric H. Brunngraber
                                               Vice President-Secretary
                                        (Chief Financial and Accounting Officer)


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                                  EXHIBIT INDEX

        Exhibit
        Number          Description
        ------          -----------

        99.1            Press Release dated October 23, 2003.


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