EXHIBIT 32.1

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

In connection with the Annual Report on Form 10-K of ReSearch Pharmaceutical Services, Inc. (the “Company”) for the year ended December 31, 2009, as filed with the Securities and Exchange Commission on the date hereof (the “Report”), I, Daniel M. Perlman, certify, pursuant to 18 U.S.C. section 1350, as adopted pursuant to section 906 of the Sarbanes-Oxley Act of 2002, that to the best of my knowledge:

(1)

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.

Dated: March 24, 2010

/s/ Daniel M. Perlman   Daniel M. Perlman
Chief Executive Officer