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

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2019-06-10</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001585855</issuerCik>
        <issuerName>Gabelli Global Small &amp; Mid Cap Value Trust</issuerName>
        <issuerTradingSymbol>GGZ</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001185533</rptOwnerCik>
            <rptOwnerName>GABELLI MARIO J</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O GAMCO INVESTORS, INC</rptOwnerStreet1>
            <rptOwnerStreet2>ONE CORPORATE CENTER</rptOwnerStreet2>
            <rptOwnerCity>RYE</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10580</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>1</isOther>
            <otherText>Control Person of Adviser</otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Shares, Par Value $0.001</value>
            </securityTitle>
            <transactionDate>
                <value>2019-06-10</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>5000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>11.5462</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>30463</value>
                    <footnoteId id="F1"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>GGCP, Inc.</value>
                    <footnoteId id="F2"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Shares, Par Value $0.001</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>2516365.43</value>
                    <footnoteId id="F1"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Shares, Par Value $0.001</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>4000</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>Gabelli &amp; Company Investment Advisers, Inc.</value>
                    <footnoteId id="F3"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Shares, Par Value $0.001</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>1358.03</value>
                    <footnoteId id="F1"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>MJG IV Limited Partnership</value>
                    <footnoteId id="F4"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Shares, Par Value $0.001</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>79769</value>
                    <footnoteId id="F1"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>Associated Capital Group, Inc.</value>
                    <footnoteId id="F5"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">Total includes shares acquired through dividend reinvestment subsequent to the initial purchase.</footnote>
        <footnote id="F2">The shares reported reflect the total shares owned by GGCP, Inc. (GGCP).  Mario J. Gabelli is the Chief Executive Officer, a director, and the controlling shareholder of GGCP.   Mr. Gabelli has less than a 100% interest in GGCP and disclaims beneficial ownership of the shares held by it which are in excess of his indirect pecuniary interest.</footnote>
        <footnote id="F3">The shares reported reflect the total shares owned by Gabelli &amp; Company Investment Advisers, Inc. (GCIA) (formally Gabelli Securities, Inc,), a majority owned subsidiary of GAMCO.  Mr. Gabelli has less than a 100% interest in GCIA and disclaims beneficial ownership of the shares held by this entity which are in excess of his indirect pecuniary interest.</footnote>
        <footnote id="F4">The shares reported reflect the total shares owned by MJG IV Limited Partnership, a limited partnership for which Mr. Gabelli serves as a general partner.  Mr. Gabelli has less than a 100% interest in the entity and disclaims beneficial ownership of the shares held by this entity which are in excess of his indirect pecuniary interest.</footnote>
        <footnote id="F5">The shares reported reflect the total shares owned by Associated Capital Group, Inc. (ACG).  Mario J. Gabelli is the Executive Chairman and controlling shareholder of ACG.  Mr. Gabelli has less than a 100% interest in ACG and disclaims beneficial ownership of the shares held by it which are in excess of his indirect pecuniary interest.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>Bruce N. Alpert as Attorney-in-Fact for Mario J. Gabelli</signatureName>
        <signatureDate>2019-06-12</signatureDate>
    </ownerSignature>
</ownershipDocument>
