EXHIBIT 23.1 ------------ CONSENT OF INDEPENDENT PUBLIC ACCOUNTANTS To SEI Investments Company: As independent public accountants, we hereby consent to the incorporation by reference in this Registration Statement of SEI Investments Company on Form S-8 of our report dated February 5, 1999 included in SEI Investments Company's Form 10-K for the year ended December 31, 1998 and to all references to our firm included in this Registration Statement. /s/ Arthur Andersen LLP Philadelphia, Pennsylvania July 23, 1999