Contacts:   Rob Stewart
                                                      Investor Relations
                                                           Pam Tomkinson
                                                         Media Relations
                                                      Tel (626) 396-8300
                                                      Fax (626) 535-0344


FOR RELEASE
-----------
October 23, 2001

              ACACIA RESEARCH DECLARES A TEN PERCENT STOCK DIVIDEND



     PASADENA,   Calif.,   October  23,  2001  -  Acacia  Research   Corporation
(Nasdaq/NMS:  ACRI)  announced  today that its Board of Directors has declared a
ten percent  (10%) stock  dividend for  shareholders  of record as of Wednesday,
November 21,  2001.  The payment  date will be December 5, 2001.  No  fractional
shares will be distributed.


ABOUT ACACIA RESEARCH CORPORATION

Acacia  Research  develops  and operates  life  science and enabling  technology
companies.  The company's core technology opportunity has been developed through
its subsidiary,  CombiMatrix  Corporation.  Acacia Research intends to build and
acquire  companies  in the life science and  material  science  fields that will
utilize CombiMatrix's  biochip technology.  Acacia Research's website is located
at www.acaciaresearch.com.



This release contains forward-looking statements within the meaning of the "safe
harbor"  provisions  of the Private  Securities  Litigation  Reform Act of 1995.
These statements  address future events and conditions  concerning the Company's
business  plans.  Such  statements  are  subject  to a  number  of  factors  and
uncertainties,  such as future economic conditions,  changes in consumer demand,
and legislative,  regulatory and competitive developments. Acacia Research urges
investors  to review in detail  the  risks and  uncertainties  disclosed  in the
Company's  filings  under  the  Securities  Exchange  Act of 1934,  as  amended,
including,  but not limited to the Company's  annual report on Form 10-K for the
year ended December 31, 2000, the Company's  quarterly reports on Form 10-Q, and
the  Company's  Registration  Statement  on Form S-3 filed on  February 6, 2001,
copies of which can be obtained from the Company or the  Securities and Exchange
Commission. The Company expressly disclaims any future obligation or undertaking
to update or revise any forward-looking statement contained herein.