February
                            18th
                            1 9 9 7




                                                      003,863-001
                                                    NB1-299234.V1
Acacia Research Corporation
12 South Raymond Avenue
Pasadena, California  91105

          Re:  Registration on Form S-8 of Acacia
               Research Corporation (the "Company")

Ladies and Gentlemen:

          At your request, we have examined the Registration
Statement on Form S-8 to be filed with the Securities and
Exchange Commission in connection with the registration under the
Securities Act of 1933, as amended, of 250,000 shares of Common
Stock, without par value, of the Company (the "Common Stock"), to
be issued pursuant to the Acacia Research Corporation 1996 Stock
Option Plan (the "Plan").  We have examined the proceedings
heretofore taken and to be taken in connection with the
authorization of the Plan and the Common Stock to be issued
pursuant to and in accordance with the Plan.

          Based upon such examination and upon such matters of
fact and law as we have deemed relevant, we are of the opinion
that the Common Stock has been duly authorized by all necessary
corporate action on the part of the Company and, when issued in
accordance with such authorization, the provisions of the Plan
and relevant agreements duly authorized by and in accordance with
the terms of the Plan, will be validly issued, fully paid and
nonassessable.

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

                              Respectfully submitted,


                              /s/ O'Melveny & Myers LLP
                              O'MELVENY & MYERS LLP