Exhibit 32.2

                            CERTIFICATION PURSUANT TO
                               U.S.C. SECTION 1350
                             AS ADOPTED PURSUANT TO
                  SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002

I, Peter C. Monson, Vice President, Treasurer and Chief Financial Officer of
Psychemedics Corporation (the "Company"), certify, pursuant to 18 U.S.C. Section
1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002,
that:

      (1)   The Company's Quarterly Report on Form 10-Q for the quarter ended
            March 31, 2004, as filed with the Securities and Exchange Commission
            on May 12, 2004 (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 Company.

Date: May 12, 2004                          By: /s/ Peter C. Monson
                                                --------------------------------
                                            Peter C. Monson
                                            Vice President, Treasurer &
                                            Chief Financial Officer

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