Exhibit 32.1


                            CERTIFICATION PURSUANT TO
                             18 U.S.C. SECTION 1350,
                             AS ADOPTED PURSUANT TO
                  SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002


In  connection  with the  Quarterly  Report  of  First  Financial  Bancorp  (the
"Company")  on Form 10-Q for the period  ending  June 30, 2003 as filed with the
Securities and Exchange  Commission on the date hereof (the  "Report"),  I, Leon
Zimmerman,  Chief  Executive  Officer of the  Company,  certify,  pursuant to 18
U.S.C.  Section 1350, as adopted  pursuant to Section 906 of the  Sarbanes-Oxley
Act of 2002, that:

         (1)      The Report fully  complies  with the  requirements  of Section
                  13(a) or 15(d) of the Securities Exchange Act of 1934; and

         (2)      The information  contained in the Report fairly  presents,  in
                  all material respects,  the financial condition and results of
                  operations of the Company.




August 12, 2003                                      /s/Leon Zimmerman
                                                     ------------------
                                                     Chief Executive Officer



A signed  original of this written  statement  required by Section 906, or other
document authenticating, acknowledging, or otherwise adopting the signature that
appears in typed form within the  electronic  version of this written  statement
required by Section 906, has been provided to First  Financial  Bancorp and will
be retained by First  Financial  Bancorp and  furnished  to the  Securities  and
Exchange Commission or its staff upon request.



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