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

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2021-08-23</periodOfReport>

    <issuer>
        <issuerCik>0000310354</issuerCik>
        <issuerName>STANDEX INTERNATIONAL CORP/DE/</issuerName>
        <issuerTradingSymbol>SXI</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001180972</rptOwnerCik>
            <rptOwnerName>HANSEN THOMAS J</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>STANDEX INTERNATIONAL CORPORATION</rptOwnerStreet1>
            <rptOwnerStreet2>23 KEEWAYDIN DRIVE, STE. 300</rptOwnerStreet2>
            <rptOwnerCity>SALEM</rptOwnerCity>
            <rptOwnerState>NH</rptOwnerState>
            <rptOwnerZipCode>03079</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
        </reportingOwnerRelationship>
    </reportingOwner>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Phantom Stock Units</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <footnoteId id="F1"/>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2021-08-23</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F2"/>
            </transactionCoding>
            <transactionTimeliness></transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>990</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <value>2024-08-23</value>
            </exerciseDate>
            <expirationDate>
                <value>2024-08-23</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>990</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>990</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">Converts on a one-to-one basis into shares of Common Stock upon vesting.</footnote>
        <footnote id="F2">Contingent Purchase of Phantom Stock of the Company pursuant to the Management Stock Purchase Plan component of the Long Term Incentive Plan vesting three years after the date of purchase in the form of Common Stock.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ Alan J. Glass</signatureName>
        <signatureDate>2021-08-25</signatureDate>
    </ownerSignature>
</ownershipDocument>
