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

    <schemaVersion>X0303</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2010-12-21</periodOfReport>

    <issuer>
        <issuerCik>0001495569</issuerCik>
        <issuerName>Motorola Mobility Holdings, Inc</issuerName>
        <issuerTradingSymbol>MMI</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0000068505</rptOwnerCik>
            <rptOwnerName>MOTOROLA INC</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>1303 E. ALGONQUIN RD.</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>SCHAUMBURG</rptOwnerCity>
            <rptOwnerState>IL</rptOwnerState>
            <rptOwnerZipCode>60103</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2010-12-21</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>J</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F1"/>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>294255263</value>
                    <footnoteId id="F2"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>0</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">The record date for the distribution by Motorola, Inc. (NYSE: MOT) (&quot;Motorola&quot;) of all the shares of Motorola Mobility Holdings, Inc. (NYSE: MMI) (&quot;Motorola Mobility&quot;) owned by Motorola to the holders of Motorola common stock was December 21, 2010 at the close of business.  The distribution of the shares is scheduled to occur on January 4, 2011.</footnote>
        <footnote id="F2">The Reporting Person owned 1,000 shares of the Issuer's outstanding common stock prior to a stock split that was effected pursuant to a Certificate of Amendment to the Restated Certificate of Incorporation of the Issuer filed with the Secretary of State of Delaware on December 15, 2010, which shares represented 100% of the Issuer's issued and outstanding common stock.  Pursuant to the stock split, each of the 1,000 shares of common stock of Motorola Mobility was subdivided and converted into 294,255.263 shares, resulting in the Reporting Person holding an aggregate of 294,255,263 shares.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>Edward J. Fitzpatrick, Senior Vice President and Chief Financial Officer, Motorola, Inc.</signatureName>
        <signatureDate>2010-12-22</signatureDate>
    </ownerSignature>
</ownershipDocument>
