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

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2020-06-22</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

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

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001667482</rptOwnerCik>
            <rptOwnerName>Brown Robert Denis</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>6500 N MINERAL DR</rptOwnerStreet1>
            <rptOwnerStreet2>SUITE 200</rptOwnerStreet2>
            <rptOwnerCity>COEUR D ALENE</rptOwnerCity>
            <rptOwnerState>ID</rptOwnerState>
            <rptOwnerZipCode>83815</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>VP - Corp. Development</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2020-06-22</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>F</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>27858</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>354325</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2020-06-22</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>52805</value>
                    <footnoteId id="F2"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>3.03</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>124560</value>
                    <footnoteId id="F3"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Performance Rights</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>0</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2020-06-22</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>34653</value>
                    <footnoteId id="F4"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <value>2023-01-01</value>
            </exerciseDate>
            <expirationDate>
                <value>2023-01-01</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>34653</value>
                    <footnoteId id="F5"/>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>609981</value>
                    <footnoteId id="F6"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">Mr. Brown was awarded (i) 34,072 restricted stock units on June 7, 2017; (ii) 52,219 restricted stock units on June 19, 2018; and (iii) 81,522 restricted stock units on June 21, 2019.  The restrictions lapsed on 1/3 of those vesting units (55,937 shares).  Mr. Brown elected to have Hecla Mining Company withhold 27,858 shares to cover his tax liability.</footnote>
        <footnote id="F2">Award of restricted stock units that vest as follows:  17,602 shares on June 21, 2021, 17,602 shares on June 21, 2022, and 17,602 shares on June 21, 2023.</footnote>
        <footnote id="F3">Total number of unvested restricted stock units held by Mr. Brown.</footnote>
        <footnote id="F4">Mr. Brown was awarded performance rights representing the contingent right to receive between $52,500 and $210,000 worth of Hecla Mining Company common stock based on Hecla Mining Company's Total Shareholder Return performance over the 3-year period (January 1, 2020 to December 31, 2022) relative to our peers.  Examples of the potential grant of shares to Mr. Brown under this plan are as follows:  100th percentile rank among peers = maximum award at 200% target ($210,000 in stock); 60th percentile rank among peers = target award at grant value ($105,000 in stock) and 50th percentile rank among peers = threshold award at 50% of target ($52,500 in stock).</footnote>
        <footnote id="F5">The number shown in Column 5 of Table II assumes a target payout (i.e., $105,000 worth of common stock), with the common stock valued at the closing price on the day of the award ($3.03).  The actual number of shares received (if any) by Mr. Brown will depend on the Total Shareholder Return performance over the 3-year period and will be determined following the termination of that period.</footnote>
        <footnote id="F6">Total consists of 354,325 shares held directly, 131,096 performance-based shares, and 124,560 unvested restricted stock units.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>Tami D. Whitman, Attorney-in-Fact for Robert D. Brown</signatureName>
        <signatureDate>2020-06-24</signatureDate>
    </ownerSignature>
</ownershipDocument>
