-----BEGIN PRIVACY-ENHANCED MESSAGE-----
Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
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MIC-Info: RSA-MD5,RSA,
 ABT4L7ZtXD7jJOig6DHQ719/g+W7rS0W0TxdCiMbDyNamB4aOLQWakni5WhmZu27
 8vhaXbYInXlTbdZ3LWOA1Q==

<SEC-DOCUMENT>0001325403-10-000003.txt : 20100106
<SEC-HEADER>0001325403-10-000003.hdr.sgml : 20100106
<ACCEPTANCE-DATETIME>20100106152056
ACCESSION NUMBER:		0001325403-10-000003
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		2
CONFORMED PERIOD OF REPORT:	20100104
FILED AS OF DATE:		20100106
DATE AS OF CHANGE:		20100106

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Hogan Karen Hanovice
		CENTRAL INDEX KEY:			0001325403

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	811-06495
		FILM NUMBER:		10511384

	MAIL ADDRESS:	
		STREET 1:		905 N. BEDFORD DRIVE
		CITY:			BEVERLY HILLS
		STATE:			CA
		ZIP:			90210

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			Flaherty & Crumrine PREFERRED INCOME OPPORTUNITY FUND INC
		CENTRAL INDEX KEY:			0000882071
		IRS NUMBER:				954355600
		STATE OF INCORPORATION:			MD
		FISCAL YEAR END:			1130

	BUSINESS ADDRESS:	
		STREET 1:		301 E COLORADO BLVD STE 720
		STREET 2:		C/O FLAHERTY & CRUMRINE INC
		CITY:			PASADENA
		STATE:			CA
		ZIP:			91101
		BUSINESS PHONE:		(626) 795-7300

	MAIL ADDRESS:	
		STREET 1:		301 COLORADO BLVD STE 720
		STREET 2:		C/O FLAHERTY & CRUMRINE INC
		CITY:			PASADENA
		STATE:			CA
		ZIP:			91101

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	PREFERRED INCOME OPPORTUNITY FUND INC
		DATE OF NAME CHANGE:	19920929
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>primary_doc.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0303</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2010-01-04</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000882071</issuerCik>
        <issuerName>Flaherty &amp; Crumrine PREFERRED INCOME OPPORTUNITY FUND INC</issuerName>
        <issuerTradingSymbol>PFO</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001325403</rptOwnerCik>
            <rptOwnerName>Hogan Karen Hanovice</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>301 EAST COLORADO BLVD</rptOwnerStreet1>
            <rptOwnerStreet2>SUITE 720</rptOwnerStreet2>
            <rptOwnerCity>PASADENA</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>91101</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2010-01-04</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>600</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>8.355</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>600</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <ownerSignature>
        <signatureName>Chad Conwell</signatureName>
        <signatureDate>2010-01-05</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
<DOCUMENT>
<TYPE>EX-24
<SEQUENCE>2
<FILENAME>pfopoahogan.txt
<DESCRIPTION>POWER OF ATTORNEY
<TEXT>


POWER OF ATTORNEY


	KNOW ALL MEN BY THESE PRESENTS, that the person
whose name appears below nominates, constitutes and
appoints Chad C. Conwell Donald F. Crumrine and Robert M.
Ettinger (with full power to act alone) her true
and lawful attorney-in-fact and agent, for her and on her
behalf and in his place and stead in any and all capacities,
to execute any and all filings on Form 4 (Statement of changes
of Beneficial Ownership of Securities) pursuant to Section
16(a) of the Securities Exchange Act of 1934 and Section
30(h) of the Investment Company Act of 1940, as amended
("Form 4 Filings") with respect to chnages of beneficial
ownership of securities of FLAHERTY & CRUMRINE PREFERRED
INCOME OOPORTUNITY FUND INCORPORATED (the "Fund"), and to
file with the Securities and Exchange Commission, The New
York Stock Exchange and the Fund such Form 4 Filings, granting
unto said attorney, full power and authority to do and perform
certain acts and things requisite and necessary to be done in
and about the premises as fully to all intents and purposes as
the undersigned herself might or could do.

	IN WITNESS WHEREOF, the undersigned has hereunto set
her hand this day of December, 2009.




Name: Karen H. Hogan
Title:   Director, Flaherty & Crumrine Preferred Income Fund
Incorporated


EXPIRES:  February 1, 2011
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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