-----BEGIN PRIVACY-ENHANCED MESSAGE-----
Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
Originator-Key-Asymmetric:
 MFgwCgYEVQgBAQICAf8DSgAwRwJAW2sNKK9AVtBzYZmr6aGjlWyK3XmZv3dTINen
 TWSM7vrzLADbmYQaionwg5sDW3P6oaM5D3tdezXMm7z1T+B+twIDAQAB
MIC-Info: RSA-MD5,RSA,
 WXHEyGttjTZCKB1CuZcvpTsMEZHnV+buL4UsAX4+RVQTH3bgBUbsb2lY7N5oEDJa
 Nw4wFDPtq97VNq6jtANZwQ==

<SEC-DOCUMENT>0001437317-10-000018.txt : 20100831
<SEC-HEADER>0001437317-10-000018.hdr.sgml : 20100831
<ACCEPTANCE-DATETIME>20100831170255
ACCESSION NUMBER:		0001437317-10-000018
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20100830
FILED AS OF DATE:		20100831
DATE AS OF CHANGE:		20100831

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			CHENU PIERRE
		CENTRAL INDEX KEY:			0001258553

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-11038
		FILM NUMBER:		101050586

	MAIL ADDRESS:	
		STREET 1:		118B AVENUE W CHURCHILL
		STREET 2:		PO BOX 15
		CITY:			BRUSSELS
		STATE:			C9
		ZIP:			1180

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			NORTHERN TECHNOLOGIES INTERNATIONAL CORP
		CENTRAL INDEX KEY:			0000875582
		STANDARD INDUSTRIAL CLASSIFICATION:	COATING, ENGRAVING & ALLIED SERVICES [3470]
		IRS NUMBER:				410857886
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			0831

	BUSINESS ADDRESS:	
		STREET 1:		4201 WOODLAND ROAD
		STREET 2:		PO BOX 69
		CITY:			CIRCLE PINES
		STATE:			MN
		ZIP:			55014
		BUSINESS PHONE:		(763) 225-6601

	MAIL ADDRESS:	
		STREET 1:		4201 WOODLAND ROAD
		STREET 2:		PO BOX 69
		CITY:			CIRCLE PINES
		STATE:			MN
		ZIP:			55014

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	NORTHERN INSTRUMENTS CORP
		DATE OF NAME CHANGE:	19930328
</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>2010-08-30</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000875582</issuerCik>
        <issuerName>NORTHERN TECHNOLOGIES INTERNATIONAL CORP</issuerName>
        <issuerTradingSymbol>NTIC</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001258553</rptOwnerCik>
            <rptOwnerName>CHENU PIERRE</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>118B AVENUE W CHURCHILL</rptOwnerStreet1>
            <rptOwnerStreet2>PO BOX 15</rptOwnerStreet2>
            <rptOwnerCity>BRUSSELS</rptOwnerCity>
            <rptOwnerState>C9</rptOwnerState>
            <rptOwnerZipCode>1180</rptOwnerZipCode>
            <rptOwnerStateDescription>BELGIUM</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>2010-08-30</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>M</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>2000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>5.75</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>6000</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Stock Option - Right to Buy</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>5.75</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2010-08-30</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>M</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>2000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>5.75</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F1"/>
            </exerciseDate>
            <expirationDate>
                <value>2010-08-31</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>2000</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>0</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">This option has fully vested</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ Matthew Wolsfeld - Attorney-in-Fact</signatureName>
        <signatureDate>2010-08-31</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
-----END PRIVACY-ENHANCED MESSAGE-----