-----BEGIN PRIVACY-ENHANCED MESSAGE-----
Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
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MIC-Info: RSA-MD5,RSA,
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 IIf3BywZAWnuhNp+SCiZaA==

<SEC-DOCUMENT>0001090091-07-000002.txt : 20071025
<SEC-HEADER>0001090091-07-000002.hdr.sgml : 20071025
<ACCEPTANCE-DATETIME>20071025100238
ACCESSION NUMBER:		0001090091-07-000002
CONFORMED SUBMISSION TYPE:	5
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20070929
FILED AS OF DATE:		20071025
DATE AS OF CHANGE:		20071025

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			INSTEEL INDUSTRIES INC
		CENTRAL INDEX KEY:			0000764401
		STANDARD INDUSTRIAL CLASSIFICATION:	STEEL WORKS, BLAST FURNACES & ROLLING & FINISHING MILLS [3310]
		IRS NUMBER:				560674867
		STATE OF INCORPORATION:			NC
		FISCAL YEAR END:			0930

	BUSINESS ADDRESS:	
		STREET 1:		1373 BOGGS DR
		CITY:			MOUNT AIRY
		STATE:			NC
		ZIP:			27030
		BUSINESS PHONE:		9107862141

	MAIL ADDRESS:	
		STREET 1:		1373 BOGGS DRIVE
		CITY:			MOUNT AIRY
		STATE:			NC
		ZIP:			27030

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	EXPOSAIC INDUSTRIES INC
		DATE OF NAME CHANGE:	19880511

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			VAUGHN RICHARD C
		CENTRAL INDEX KEY:			0001017473

	FILING VALUES:
		FORM TYPE:		5
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-09929
		FILM NUMBER:		071189746

	BUSINESS ADDRESS:	
		BUSINESS PHONE:		9107862141

	MAIL ADDRESS:	
		STREET 1:		1373 BOGGS DR
		CITY:			MT AIRY
		STATE:			NC
		ZIP:			27030
</SEC-HEADER>
<DOCUMENT>
<TYPE>5
<SEQUENCE>1
<FILENAME>primary_doc.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0202</schemaVersion>

    <documentType>5</documentType>

    <periodOfReport>2007-09-29</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <form3HoldingsReported>0</form3HoldingsReported>

    <form4TransactionsReported>0</form4TransactionsReported>

    <issuer>
        <issuerCik>0000764401</issuerCik>
        <issuerName>INSTEEL INDUSTRIES INC</issuerName>
        <issuerTradingSymbol>IIIN</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001017473</rptOwnerCik>
            <rptOwnerName>VAUGHN RICHARD C</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>1373 BOGGS DR</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>MT AIRY</rptOwnerCity>
            <rptOwnerState>NC</rptOwnerState>
            <rptOwnerZipCode>27030</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>2006-12-06</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>5</transactionFormType>
                <transactionCode>G</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>5017</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>31269</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2007-06-06</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>5</transactionFormType>
                <transactionCode>G</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>5477</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>27720</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionCoding>
                <transactionFormType></transactionFormType>
            </transactionCoding>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>2345</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>Restricted</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <ownerSignature>
        <signatureName>James F. Petelle for C. Richard Vaughn</signatureName>
        <signatureDate>2007-10-25</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
-----END PRIVACY-ENHANCED MESSAGE-----