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

    <schemaVersion>X0609</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2026-06-10</periodOfReport>

    <issuer>
        <issuerCik>0000798783</issuerCik>
        <issuerName>UNIVERSAL HEALTH REALTY INCOME TRUST</issuerName>
        <issuerTradingSymbol>UHT</issuerTradingSymbol>
        <issuerForeignTradingSymbol></issuerForeignTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001180997</rptOwnerCik>
            <rptOwnerName>RAMAGANO CHERYL K</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerNonUSAddressFlag>false</rptOwnerNonUSAddressFlag>
            <rptOwnerStreet1>UNIVERSAL CORPORATE CENTER</rptOwnerStreet1>
            <rptOwnerStreet2>367 SOUTH GULPH ROAD</rptOwnerStreet2>
            <rptOwnerCity>KING OF PRUSSIA</rptOwnerCity>
            <rptOwnerState>PA</rptOwnerState>
            <rptOwnerZipCode>19406</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isOfficer>1</isOfficer>
            <officerTitle>SVP, Operations and Treasurer</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <aff10b5One>0</aff10b5One>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Shares Of Beneficial Interest</value>
            </securityTitle>
            <transactionDate>
                <value>2026-06-10</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness></transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>3631</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>49611</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">These restricted shares of beneficial interest were granted pursuant to the Amended and Restated Universal Health Realty Income Trust 2007 Restricted Stock Plan and shall vest on the second anniversary of the grant date.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ Charles F. Boyle, Attorney-in-Fact for Ms. Ramagano</signatureName>
        <signatureDate>2026-06-11</signatureDate>
    </ownerSignature>
</ownershipDocument>
