<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0303</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2008-09-11</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001108320</issuerCik>
        <issuerName>SMTC CORP</issuerName>
        <issuerTradingSymbol>SMTX</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001325533</rptOwnerCik>
            <rptOwnerName>Red Oak Partners, LLC</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>145 FOURTH AVENUE</rptOwnerStreet1>
            <rptOwnerStreet2>SUITE 15A</rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10003</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001397261</rptOwnerCik>
            <rptOwnerName>Red Oak Fund, LP</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>145 FOURTH AVENUE</rptOwnerStreet1>
            <rptOwnerStreet2>SUITE 15A</rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10003</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001423093</rptOwnerCik>
            <rptOwnerName>Sandberg David</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>145 FOURTH AVENUE</rptOwnerStreet1>
            <rptOwnerStreet2>SUITE 15A</rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10003</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 ($.01 par value)</value>
            </securityTitle>
            <transactionDate>
                <value>2008-09-11</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>J</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>288112</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>1.77</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>2383311</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By the Red Oak Fund, LP</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock ($.01 par value)</value>
            </securityTitle>
            <transactionDate>
                <value>2008-09-11</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>J</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>288112</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>1.77</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>2383311</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By Pinnacle Fund LLLP</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <remarks>#	Footnotes
1	On September 11, 2008, Red Oak Partners, L.P. distributed 288,112 shares of Common Stock ($.01 Par Value) of SMTC Corp. to certain limited partners of Red Oak Partners, L.P. (including David Sandberg).  Such limited partners (including David Sandberg) simultaneously with such distribution contributed all 288,112 shares of Common Stock ($.01 Par Value) of SMTC Corp to Pinnacle Fund LLLP in exchange for limited partnership interests in Pinnacle Fund LLLP.
2	Red Oak Partners, LLC (the &quot;General Partner&quot;) serves as the general partner of The Red Oak Fund, LP, a Delaware limited partnership (the &quot;Fund&quot;), the direct owner of the subject securities.  David Sandberg is the managing member of the General Partner and the Fund's portfolio manager.  Each Reporting Person disclaims beneficial ownership of all securities reported herein, except to the extent of their pecuniary interest therein, if any, and this report shall not be deemed an admission that such Reporting Person is the beneficial owner of the shares for purposes of Section 16 of the Securities and Exchange Act of 1934 or for any other purpose.
3	Not Applicable.
4	Red Oak Partners, LLC (the &quot;General Partner&quot;) serves as a general partner of Pinnacle Fund LLLP, a Colorado limited liability limited partnership (&quot;Pinnacle&quot;), the direct owner of the subject securities.  David Sandberg is a limited partner of Pinnacle, the managing member of the General Partner and an investment advisor to Pinnacle.  Each Reporting Person disclaims beneficial ownership of all securities reported herein, except to the extent of their pecuniary interest therein, if any, and this report shall not be deemed an admission that such Reporting Person is the beneficial owner of the shares for purposes of Section 16 of the Securities and Exchange Act of 1934 or for any other purpose.</remarks>

    <ownerSignature>
        <signatureName>David Sandberg</signatureName>
        <signatureDate>2008-09-23</signatureDate>
    </ownerSignature>
</ownershipDocument>
