<DOCUMENT>
<TYPE>EX-99.906
<SEQUENCE>3
<FILENAME>cert906.txt
<DESCRIPTION>906 CERT
<TEXT>
         CERTIFICATION PURSUANT TO RULE 30A-2(B) UNDER THE 1940 ACT AND
                      SECTION 906 OF THE SARBANES-OXLEY ACT

I,  Donald F.  Crumrine,  Director,  Chairman  of the Board and Chief  Executive
Officer  of  Flaherty  & Crumrine Preferred Income Opportunity Fund Incorporated
(the "Registrant"), certify that:

         1.     The Form N-CSR of the Registrant (the "Report")  fully  complies
                with  the  requirements  of  Section  13(a)  or  15(d)  of   the
                Securities Exchange Act of 1934, as amended; and

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


Date:    JULY 18, 2005                         /S/ DONALD F. CRUMRINE
     -------------------------     ---------------------------------------------
                                   Donald F. Crumrine, Director, Chairman of the
                                   Board and Chief Executive Officer
                                   (principal executive officer)


I, R. Eric  Chadwick,  Chief  Financial  Officer, Treasurer, Vice President  and
Secretary of Flaherty & Crumrine  Preferred Income Opportunity Fund Incorporated
(the "Registrant"), certify that:

         1.     The Form N-CSR of the Registrant (the "Report")  fully  complies
                with  the  requirements  of  Section  13(a)  or   15(d)  of  the
                Securities Exchange Act of 1934, as amended; and

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


Date:    JULY 18, 2005                           /S/ R. ERIC CHADWICK
     -----------------------          ------------------------------------------
                                      R. Eric Chadwick, Chief Financial Officer,
                                      Treasurer, Vice President and Secretary
                                      (principal financial officer)

</TEXT>
</DOCUMENT>
