-----BEGIN PRIVACY-ENHANCED MESSAGE-----
Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
Originator-Key-Asymmetric:
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MIC-Info: RSA-MD5,RSA,
 PVXPTuotCnOj8cV1tw5UksXlTJ+/dl2WwZxBL3AEX/s2bUcbbJzB0c/j2da5kkei
 GezByV5b7OqJm0Jo459UPg==

<SEC-DOCUMENT>0001249781-04-000019.txt : 20040521
<SEC-HEADER>0001249781-04-000019.hdr.sgml : 20040521
<ACCEPTANCE-DATETIME>20040521182541
ACCESSION NUMBER:		0001249781-04-000019
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20040510
FILED AS OF DATE:		20040521

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			INCOME OPPORTUNITY REALTY INVESTORS INC /TX/
		CENTRAL INDEX KEY:			0000949961
		STANDARD INDUSTRIAL CLASSIFICATION:	REAL ESTATE INVESTMENT TRUSTS [6798]
		IRS NUMBER:				752615944
		STATE OF INCORPORATION:			NV
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		1800 VALLEY VIEW LANE
		STREET 2:		SUITE 300
		CITY:			DALLAS
		STATE:			TX
		ZIP:			75234
		BUSINESS PHONE:		4685224200

	MAIL ADDRESS:	
		STREET 1:		1800 VALLEY VIEW LANE
		STREET 2:		SUITE 300
		CITY:			DALLAS
		STATE:			TX
		ZIP:			75234

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			SYNTEK WEST INC
		CENTRAL INDEX KEY:			0001241255
		STATE OF INCORPORATION:			NV
		FISCAL YEAR END:			0630

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-14784
		FILM NUMBER:		04825262

	BUSINESS ADDRESS:	
		STREET 1:		1800 VALLEY VIEW LANE SUITE 100
		CITY:			DALLAS
		STATE:			TX
		ZIP:			75234
		BUSINESS PHONE:		2147505800

	MAIL ADDRESS:	
		STREET 1:		1800 VALLEY VIEW LANE SUITE 100
		CITY:			DALLAS
		STATE:			TX
		ZIP:			75234
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>primary_doc.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0202</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2004-05-10</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000949961</issuerCik>
        <issuerName>INCOME OPPORTUNITY REALTY INVESTORS INC /TX/</issuerName>
        <issuerTradingSymbol>IOT</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001241255</rptOwnerCik>
            <rptOwnerName>SYNTEK WEST INC</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>1800 VALLEY VIEW LANE SUITE 100</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>DALLAS</rptOwnerCity>
            <rptOwnerState>TX</rptOwnerState>
            <rptOwnerZipCode>75234</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock par value $0.01</value>
            </securityTitle>
            <transactionDate>
                <value>2004-05-07</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>150</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>13.8</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>794223</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By subsidiary Syntek Acquisition Corp.</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <remarks>Shares were sold by the broker by mistake.</remarks>

    <ownerSignature>
        <signatureName>/s/ Louis J. Corna</signatureName>
        <signatureDate>2004-05-21</signatureDate>
    </ownerSignature>
</ownershipDocument>

</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
-----END PRIVACY-ENHANCED MESSAGE-----
