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

    <schemaVersion>X0206</schemaVersion>

    <documentType>3</documentType>

    <periodOfReport>2021-12-31</periodOfReport>

    <noSecuritiesOwned>0</noSecuritiesOwned>

    <issuer>
        <issuerCik>0000051143</issuerCik>
        <issuerName>INTERNATIONAL BUSINESS MACHINES CORP</issuerName>
        <issuerTradingSymbol>IBM</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001576105</rptOwnerCik>
            <rptOwnerName>Rosamilia Thomas W</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>IBM CORPORATION</rptOwnerStreet1>
            <rptOwnerStreet2>ONE NEW ORCHARD ROAD</rptOwnerStreet2>
            <rptOwnerCity>ARMONK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10504</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>false</isDirector>
            <isOfficer>true</isOfficer>
            <isTenPercentOwner>false</isTenPercentOwner>
            <isOther>false</isOther>
            <officerTitle>Senior Vice President</officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>17830.812</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <derivativeTable>
        <derivativeHolding>
            <securityTitle>
                <value>Rst. Stock Unit</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>0.00</value>
            </conversionOrExercisePrice>
            <exerciseDate>
                <footnoteId id="F1"/>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F1"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>3108.00</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeHolding>
        <derivativeHolding>
            <securityTitle>
                <value>Rst. Stock Unit</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>0.00</value>
            </conversionOrExercisePrice>
            <exerciseDate>
                <footnoteId id="F2"/>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F2"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>7774.00</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeHolding>
        <derivativeHolding>
            <securityTitle>
                <value>Rst. Stock Unit</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>0.00</value>
            </conversionOrExercisePrice>
            <exerciseDate>
                <footnoteId id="F3"/>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F3"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>13210.00</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeHolding>
        <derivativeHolding>
            <securityTitle>
                <value>Rst. Stock Unit</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>0.00</value>
            </conversionOrExercisePrice>
            <exerciseDate>
                <footnoteId id="F4"/>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F4"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>16271.00</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeHolding>
        <derivativeHolding>
            <securityTitle>
                <value>Phantom Stock Unit</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>0.00</value>
            </conversionOrExercisePrice>
            <exerciseDate>
                <footnoteId id="F5"/>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F5"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>24355.00</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeHolding>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">On 6/8/18, the reporting person was granted 12,032 RSUs, 3,008 of which vested on 6/8/19, 3,008 of which vested on 6/8/20, 3,008 of which vested on 6/8/21, and 3,008 of which will vest on 6/8/22.  In connection with the spin-off of Kyndryl Holdings, Inc. on November 3, 2021, unvested Issuer restricted stock units were adjusted to reflect additional restricted stock units, which additional restricted stock units are included in the figures above.</footnote>
        <footnote id="F2">On 6/7/19, the reporting person was granted 15,046 RSUs, 3,761 of which vested on 6/7/20, 3,761 of which vested on 6/7/21, 3,761 of which will vest on 6/7/22, and 3,763 of which will vest on 6/7/23. In connection with the spin-off of Kyndryl Holdings, Inc. on November 3, 2021, unvested Issuer restricted stock units were adjusted to reflect additional restricted stock units, which additional restricted stock units are included in the figures above.</footnote>
        <footnote id="F3">On 6/8/20, the reporting person was granted 17,048 RSUs, 4,262 which vested on 6/8/21, 4,262 of which     will vest on 6/8/22, 4,262 of which will vest on 6/8/23, and 4,262 of which will vest on 6/8/24. In connection with the spin-off of Kyndryl Holdings, Inc. on November 3, 2021, unvested Issuer restricted stock units were adjusted to reflect additional restricted stock units, which additional restricted stock units are included in the figures above.</footnote>
        <footnote id="F4">On 6/8/21, the reporting person was granted 15,748 RSUs, 3,937 of which will vest on 6/8/22, 3,937 of which will vest on 6/8/23, 3,937 of which will vest on 6/8/24, and 3,937 of which will vest on 6/8/25. In connection with the spin-off of Kyndryl Holdings, Inc. on November 3, 2021, unvested Issuer restricted stock units were adjusted to reflect additional restricted stock units, which additional restricted stock units are included in the figures above.</footnote>
        <footnote id="F5">Phantom stock units acquired under the IBM Excess 401 (k) Plus Plan convert to the cash value of the company's common stock on a one-for-one basis, and distribution is deferred until separation from the company.  The reporting person may transfer these phantom stock units into an alternative investment account under such plan.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>D. Glowienka on behalf of T. Rosamilia</signatureName>
        <signatureDate>2022-01-04</signatureDate>
    </ownerSignature>
</ownershipDocument>
