<?xml version="1.0"?>

<ownershipDocument>

    <documentType>3</documentType>

    <periodOfReport>2003-04-21</periodOfReport>


    <noSecuritiesOwned>0</noSecuritiesOwned>

    <issuer>
        <issuerCik>0000901823</issuerCik>
        <issuerName>PUTNAM MANAGED HIGH YIELD TRUST</issuerName>
        <issuerTradingSymbol>ptm</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001231820</rptOwnerCik>
            <rptOwnerName>ROBIE RICHARD S III</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>  </rptOwnerStreet1>
            <rptOwnerStreet2>  </rptOwnerStreet2>
            <rptOwnerCity>  </rptOwnerCity>
            <rptOwnerState>  </rptOwnerState>
            <rptOwnerZipCode>  </rptOwnerZipCode>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>Managing Director, Putnam, LLC</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeSecurity>
        <securityTitle>
            <value>Closed-End Fund</value>
        </securityTitle>
        <transactionAmounts>
            <transactionShares>
                <value>0</value>
            </transactionShares>
        </transactionAmounts>
        <ownershipNature>
            <directOrIndirectOwnership>
                <value>D</value>
            </directOrIndirectOwnership>
        </ownershipNature>
    </nonDerivativeSecurity>


    <ownerSignature>
        <signatureName>Richard S. Robie III, Putnam, LLC</signatureName>
        <signatureDate>2003-05-14</signatureDate>
    </ownerSignature>

</ownershipDocument>

