SEI Investments (SEIC) 10-Q 2004 Q1 Quarterly report

Exhibit 32

SECTION 1350 CERTIFICATIONS

I, Alfred P. West, Jr., Chairman and Chief Executive Officer, and I, Dennis J. McGonigle, Chief Financial Officer, of SEI Investments Company, a Pennsylvania corporation (the “Company”), hereby certify that, to my knowledge:

(1) The Company’s Quarterly Report on Form 10-Q for the quarterly period ended March 31, 2004 (the “Form 10-Q”) fully complies with the requirements of Section 13(a) of the Securities Exchange Act of 1934; and

(2) The information contained in the Form 10-Q fairly presents, in all material respects, the financial condition and results of operations of the Company.

Date: May 10, 2004	Date: May 10, 2004
/s/ Alfred P. West, Jr.	/s/ Dennis J. McGonigle
Alfred P. West, Jr.	Dennis J. McGonigle
Chairman and Chief Executive Officer	Chief Financial Officer