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

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2015-06-15</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000719413</issuerCik>
        <issuerName>HECLA MINING CO/DE/</issuerName>
        <issuerTradingSymbol>HL</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001166074</rptOwnerCik>
            <rptOwnerName>BAKER PHILLIPS S JR</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>6500 NORTH MINERAL DRIVE</rptOwnerStreet1>
            <rptOwnerStreet2>SUITE 200</rptOwnerStreet2>
            <rptOwnerCity>COEUR D 'ALENE</rptOwnerCity>
            <rptOwnerState>ID</rptOwnerState>
            <rptOwnerZipCode>83815</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>President and CEO</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2015-06-15</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>J</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>11826</value>
                </transactionShares>
                <transactionPricePerShare>
                    <footnoteId id="F1"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>1590362</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">Common stock acquired pursuant to Agreement and Plan of Merger among Revett Mining Company, Inc. (&quot;Revett&quot;), Hecla Mining Company (&quot;Hecla&quot;) and RHL Holdings, Inc., a wholly-owned subsidiary of Hecla (&quot;Merger Sub&quot;), whereby Merger Sub was merged with and into Revett (the &quot;Merger&quot;) and each share of common stock of Revett was converted into 0.1622 of a share of Hecla common stock, resulting in the receipt of 11,826 shares of Hecla common stock in exchange for 72,917 shares of Revett common stock owned by the reporting person.  The closing price of Hecla common stock on June 15, 2015, the effective date of the Merger, was $3.06.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>Tami D. Whitman, Attorney-in-Fact for Phillips S. Baker, Jr.</signatureName>
        <signatureDate>2015-06-17</signatureDate>
    </ownerSignature>
</ownershipDocument>
