EXHIBIT 5
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                                ARCHER & GREINER
                           A Professional Corporation

                                COUNSELORS AT LAW
                              ONE CENTENNIAL SQUARE
                                 P. O. BOX 3000
                       HADDONFIELD, NEW JERSEY 08033-0968


                                                                  May 31, 2001

eResearchTechnology, Inc.
30 S. 17th Street
Philadelphia, PA 19103

Dear Sirs:

         We have examined the corporate records and proceedings of
eResearchTechnology, Inc., a Delaware corporation, with respect to the legal
sufficiency of all corporate proceedings of such corporation taken in connection
with the creation, form and validity and full payment and non-assessability when
issued of the 300,000 shares of common stock, par value $0.01 per share, covered
by the Registration Statement on Form S-8, dated May 31, 2001 in connection with
which Registration Statement this opinion is rendered.

         Based upon such examination, we are of the opinion that when the
Registration Statement shall have been declared effective by order of the
Securities and Exchange Commission, and the shares shall have been issued and
sold upon the terms and conditions set forth in the Registration Statement, such
shares will be validly authorized and legally issued, fully paid, and
non-assessable.

         We hereby consent to the filing of this opinion as an exhibit to the
Registration Statement.

                                                     Sincerely,

                                                     /s/ Archer & Greiner
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                                                     ARCHER & GREINER
                                                     A Professional Corporation