EXHIBIT 5

                   Opinion of Brobeck, Phleger & Harrison LLP

                               August 20, 1997



FileNet Corporation
3565 Harbor Boulevard
Costa Mesa, CA  92626

           Re:      FileNet Corporation (the "Company")
                    Registration Statement for Registration
                    of 1,130,000 Shares of Common Stock


Ladies and Gentlemen:

     We refer to your  registration on Form S-8 (the  "Registration  Statement")
under the  Securities  Act of 1933,  as amended,  of (i) an  additional  600,000
shares of Common Stock for issuance  under the Company's 1995 Stock Option Plan,
(ii) an  additional  150,000  shares of  Common  Stock  for  issuance  under the
Company's 1988 Employee  Qualified Stock Purchase Plan,  (iii) 300,000 shares of
Common Stock for issuance pursuant to a Written  Compensation  Agreement between
the Company and Mr. Lee D.  Roberts and (iv) 80,000  shares of Common  Stock for
issuance  pursuant to a Written  Compensation  Agreement between the Company and
Mr. Ron L. Ercanbrack. We advise you that, in our opinion, when such shares have
been issued and sold pursuant to the applicable provisions of the Company's 1995
Stock Option Plan,  the Company's 1988 Employee  Qualified  Stock Purchase Plan,
the Written Compensation Agreement with Mr. Roberts and the Written Compensation
Agreement with Mr. Ercanbrack and in accordance with the Registration Statement,
such shares will be validly issued, fully paid and non-assessable  shares of the
Company's Common Stock.

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

                                             Very truly yours,

                                             /s/ BROBECK, PHLEGER & HARRISON LLP

                         BROBECK, PHLEGER & HARRISON LLP


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