Exhibit 32.1

Certification Pursuant to Section 906 of the Sarbanes-Oxley Act of 2002

In connection with the filing of the Quarterly Report on Form 10-Q for the
Quarter ended June 30, 2003 (the "Report") by Cellular Technical Services
Company, Inc. ("registrant"), each of the undersigned hereby certifies that:

     1.   The Report fully complies with the requirements of section 13(a) or
          15(d) of the Securities Exchange Act of 1934, as amended, and

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


               By: /s/ Stephen Katz
                   ------------------------------------------
                   Stephen Katz
                   Chief Executive Officer
                   August 14, 2003


               By: /s/ Bruce R. York
                   ------------------------------------------
                   Bruce R. York
                   Vice President and Chief Financial Officer
                   August 14, 2003

A signed original of this written statement required by Section 906 has been
provided to Cellular Technical Services Company, Inc. and will be retained by
Cellular Technical Services Company, Inc. and furnished to the Securities and
Exchange Commission or its staff upon request.