<SEC-DOCUMENT>0001526513-18-000002.txt : 20180905
<SEC-HEADER>0001526513-18-000002.hdr.sgml : 20180905
<ACCEPTANCE-DATETIME>20180905164705
ACCESSION NUMBER:		0001526513-18-000002
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20180901
FILED AS OF DATE:		20180905
DATE AS OF CHANGE:		20180905

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Keong Koh Soo
		CENTRAL INDEX KEY:			0001434271

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-11038
		FILM NUMBER:		181055627

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

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>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2018-09-01</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

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

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001434271</rptOwnerCik>
            <rptOwnerName>Keong Koh Soo</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>4201 WOODLAND ROAD</rptOwnerStreet1>
            <rptOwnerStreet2>POST OFFICE BOX 69</rptOwnerStreet2>
            <rptOwnerCity>CIRCLE PINES</rptOwnerCity>
            <rptOwnerState>MN</rptOwnerState>
            <rptOwnerZipCode>55014</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>16666</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Stock Option (right to buy)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>36.45</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2018-09-01</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>2773</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <value>2019-09-01</value>
            </exerciseDate>
            <expirationDate>
                <value>2028-08-31</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>2773</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>2773</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <ownerSignature>
        <signatureName>/s/ Matthew C. Wolsfeld - Attorney-in-fact</signatureName>
        <signatureDate>2018-09-05</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
