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

    <schemaVersion>X0305</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2012-05-22</periodOfReport>

    <issuer>
        <issuerCik>0000068505</issuerCik>
        <issuerName>Motorola Solutions, Inc.</issuerName>
        <issuerTradingSymbol>MSI</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001082870</rptOwnerCik>
            <rptOwnerName>DORMAN DAVID W</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>MOTOROLA SOLUTIONS, INC.</rptOwnerStreet1>
            <rptOwnerStreet2>1303 E. ALGONQUIN ROAD</rptOwnerStreet2>
            <rptOwnerCity>SCHAUMBURG</rptOwnerCity>
            <rptOwnerState>IL</rptOwnerState>
            <rptOwnerZipCode>60196</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Motorola Solutions, Inc. - Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2012-05-22</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>16130</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>47.88</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>50507.6385</value>
                    <footnoteId id="F2"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">Deferred stock units (DSUs) to be settled in shares of Motorola Solutions Inc. common stock upon termination of service from the Motorola Solutions, Inc. Board of Directors.  These DSUs were acquired in lieu of the right to receive cash in connection with the acquisition of Motorola Mobility Holdings, Inc. by Google Inc., for the 19,308 DSUs relating to shares of common stock of Motorola Mobility Holdings. Inc.  The Motorola Mobility Holdings, Inc. DSUs were originally received as dividend equivalent rights in connection with the separation of Motorola Mobility Holdings, Inc. from Motorola Inc.</footnote>
        <footnote id="F2">Includes Deferred Stock Units received pursuant to dividend equivalent rights which were credited to the reporting person when and as dividends were paid on Motorola Solutions, Inc. common stock.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>Kristin L. Kruska, on behalf of David W. Dorman Director, Motorola Solutions, Inc. (Power of Attorney on File)</signatureName>
        <signatureDate>2012-05-24</signatureDate>
    </ownerSignature>
</ownershipDocument>
