<SEC-DOCUMENT>0001387131-17-005132-index.html : 20171024
<SEC-HEADER>0001387131-17-005132.hdr.sgml : 20171024
<ACCEPTANCE-DATETIME>20171024085437
ACCESSION NUMBER:		0001387131-17-005132
CONFORMED SUBMISSION TYPE:	N-30B-2
PUBLIC DOCUMENT COUNT:		3
CONFORMED PERIOD OF REPORT:	20170831
FILED AS OF DATE:		20171024
DATE AS OF CHANGE:		20171024
EFFECTIVENESS DATE:		20171024

FILER:

	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

	FILING VALUES:
		FORM TYPE:		N-30B-2
		SEC ACT:		1940 Act
		SEC FILE NUMBER:	811-06495
		FILM NUMBER:		171150021

	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>N-30B-2
<SEQUENCE>1
<FILENAME>pfo-n30b2_083117.htm
<DESCRIPTION>REPORT TO INVESTMENT COMPANY SHAREHOLDERS
<TEXT>
Document 1 - file: pfo-n30b2_083117.htm

</DOCUMENT>
<DOCUMENT>
<TYPE>GRAPHIC
<SEQUENCE>2
<FILENAME>flahertyqrtrpt083117001.jpg
<DESCRIPTION>GRAPHIC
<TEXT>
Document 2 - file: flahertyqrtrpt083117001.jpg

</DOCUMENT>
<DOCUMENT>
<TYPE>GRAPHIC
<SEQUENCE>3
<FILENAME>flahertyqrtrpt083117002.jpg
<DESCRIPTION>GRAPHIC
<TEXT>
Document 3 - file: flahertyqrtrpt083117002.jpg

</DOCUMENT>
</SEC-DOCUMENT>