-----BEGIN PRIVACY-ENHANCED MESSAGE-----
Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
Originator-Key-Asymmetric:
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 TWSM7vrzLADbmYQaionwg5sDW3P6oaM5D3tdezXMm7z1T+B+twIDAQAB
MIC-Info: RSA-MD5,RSA,
 NnmIlCunFFgR9r/ZaApuLGUTCulfDgncnDgaamYMrKw+GDwa5qVKvIHmCC0frZT8
 WXOInrk+mxcu9jbEyQOnHw==

<SEC-DOCUMENT>0001235802-10-000197.txt : 20101216
<SEC-HEADER>0001235802-10-000197.hdr.sgml : 20101216
<ACCEPTANCE-DATETIME>20101216163812
ACCESSION NUMBER:		0001235802-10-000197
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20101215
FILED AS OF DATE:		20101216
DATE AS OF CHANGE:		20101216

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			DEMOREST ROBERT L
		CENTRAL INDEX KEY:			0001239192

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-09273
		FILM NUMBER:		101257231

	MAIL ADDRESS:	
		STREET 1:		2235 VALE CREST
		CITY:			MINNEAPOLIS
		STATE:			MN
		ZIP:			55422

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			MOCON INC
		CENTRAL INDEX KEY:			0000067279
		STANDARD INDUSTRIAL CLASSIFICATION:	MEASURING & CONTROLLING DEVICES, NEC [3829]
		IRS NUMBER:				410903312
		STATE OF INCORPORATION:			MN
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		7500 MENDELSSOHN AVE N
		CITY:			MINNEAPOLIS
		STATE:			MN
		ZIP:			55428
		BUSINESS PHONE:		6124936370

	MAIL ADDRESS:	
		STREET 1:		7500 MENDELSSOHN AVE N
		CITY:			MINNEAPOLIS
		STATE:			MN
		ZIP:			55428

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	MODERN CONTROLS INC
		DATE OF NAME CHANGE:	19920703
</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>2010-12-15</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000067279</issuerCik>
        <issuerName>MOCON INC</issuerName>
        <issuerTradingSymbol>MOCO</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001239192</rptOwnerCik>
            <rptOwnerName>DEMOREST ROBERT L</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O MOCON, INC.</rptOwnerStreet1>
            <rptOwnerStreet2>7500 MENDELSSOHN AVENUE N.</rptOwnerStreet2>
            <rptOwnerCity>MINNEAPOLIS</rptOwnerCity>
            <rptOwnerState>MN</rptOwnerState>
            <rptOwnerZipCode>55428</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>Chairman, President &amp; CEO</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2010-12-15</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>850</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>12.5</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>154542</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <ownerSignature>
        <signatureName>/s/ Robert L. Demorest</signatureName>
        <signatureDate>2010-12-16</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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