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EXHIBIT 5.--OPINION OF COUNSEL


                               FROST & JACOBS LLP
                                 2500 PNC Center
                              201 East Fifth Street
                              Post Office Box 5715
                           Cincinnati, Ohio 45201-5715
                                 (513) 651-6800


                                                March 3, 1999


First Financial Bancorp.
300 High Street
Hamilton, Ohio  45012-0476

         Re:      First Financial Bancorp.
                  Form S-4 Registration Statement
                  -------------------------------

Gentlemen:

         We are counsel for First Financial Bancorp., an Ohio corporation (the
"Company"), which is named as the registrant in the Registration Statement on
Form S-4 which is being filed on or about March 3, 1999 with the Securities and
Exchange Commission for the purpose of registering under the Securities Act of
1933, as amended (the "Act"), certain common shares, without par value (the
"Common Shares"), of the Company.

         With respect to the Common Shares being registered pursuant to such
Registration Statement as filed and as it may be amended, it is our opinion that
the Common Shares, when issued and paid for pursuant to the Plan and Agreement
of Merger dated as of December 16, 1998 between First Financial Bancorp. and
Sand Ridge Financial Corporation, will be validly issued, fully paid and
non-assessable.

         We hereby consent to the reference to our firm under the caption "Legal
Matters" in the Registration Statement.

                                             Very Truly Yours,
                                             Frost & Jacobs LLP

NG/gam