Exhibit 99.1 Certification of Chief Executive Officer and Chief Financial Officer Each of the undersigned officers hereby certifies that, to his knowledge, (1) the Quarterly Report on Form 10-Q of COMFORCE Corporation for the quarter ended June 30, 2002 as to which this Certification is an exhibit fully complies with the requirements of Section 13(a) or 15(d) of the Securities Exchange Act of 1934 (15 U.S.C. 78m(a) or 78o(d)) and (2) the information contained in such Report fairly presents, in all material respects, the financial condition and results of operations of COMFORCE Corporation. Signed this 13th day of August, 2002. /s/ John C. Fanning - --------------------------------- John C. Fanning Chairman of the Board and Chief Executive Officer /s/ Harry V. Maccarrone - --------------------------------- Harry V. Maccarrone Executive Vice President and Chief Financial Officer