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

    <schemaVersion>X0202</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2004-05-12</periodOfReport>

    <issuer>
        <issuerCik>0000829608</issuerCik>
        <issuerName>PSYCHIATRIC SOLUTIONS INC</issuerName>
        <issuerTradingSymbol>PSYS</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001199270</rptOwnerCik>
            <rptOwnerName>LAMONT ANN H</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O OAK INVESTMENT PARTNERS</rptOwnerStreet1>
            <rptOwnerStreet2>ONE GORHAM ISLAND</rptOwnerStreet2>
            <rptOwnerCity>WESTPORT</rptOwnerCity>
            <rptOwnerState>CT</rptOwnerState>
            <rptOwnerZipCode>06880</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0000933938</rptOwnerCik>
            <rptOwnerName>OAK INVESTMENT PARTNERS VI LP</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>ONE GORHAM ISLAMD</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>WESTPORT</rptOwnerCity>
            <rptOwnerState>CT</rptOwnerState>
            <rptOwnerZipCode>06880</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001131676</rptOwnerCik>
            <rptOwnerName>OAK INVESTMENT PARTNERS X LTD PARTNERSHIP</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>ONE GORHAM ISLAND</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>WESTPORT</rptOwnerCity>
            <rptOwnerState>CT</rptOwnerState>
            <rptOwnerZipCode>06880</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001143824</rptOwnerCik>
            <rptOwnerName>OAK X AFFILIATES FUND LP</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>ONE GORHAM ISLAND</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>WESTPORT</rptOwnerCity>
            <rptOwnerState>CT</rptOwnerState>
            <rptOwnerZipCode>06880</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>2004-05-12</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>473</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>23.06</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>0</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See Note</value>
                    <footnoteId id="F1"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>2792</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">Represents shares directly owned by Oak Investment Partners VI, Limited Partnership.</footnote>
    </footnotes>

    <remarks>Ann H. Lamont is a Director of Psychiatric Solutions, Inc.  Ms. Lamont is a Managing Member of Oak Associates VI, L.L.C., the General Partner of Oak Investment Partners VI, Limited Partnership (&quot;Oak VI, LP); a Managing Member of Oak Associates X, L.L.C., the General Partner of Oak Investment Partners X, Limited Partnership; and a Managing Member of Oak X Affiliates, L.L.C., the General Partner of Oak X Affiliates Fund, Limited Partnership.

Oak VI, LP is no longer subject to Section 16 because Oak VI, LP ceased to beneficially own any shares of Common Stock on May 12, 2004.

Each Reporting Person disclaims the existence of a &quot;group&quot; and disclaims beneficial ownership of any securities (except to the extent of such Reporting Person's pecuniary interest in such securities) other than any securities reported herein as being directly owned by such Reporting Person, and this report shall not be deemed an admission that such Reporting Person is the beneficial owner of any such securities for purposes of Section 16 or for any other purpose.</remarks>

    <ownerSignature>
        <signatureName>Ann H. Lamont</signatureName>
        <signatureDate>2004-05-12</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>Ann H. Lamont, Managing Member of Oak Associates VI, L.L.C., the General Partner of Oak Investment Partners VI, Limited Partnership</signatureName>
        <signatureDate>2004-05-12</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>Ann H. Lamont, Managing Member of Oak Associates X, L.L.C., the General Partner of Oak Investment Partners X, Limited Partnership</signatureName>
        <signatureDate>2004-05-12</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>Ann H. Lamont, Managing Member of Oak X Affiliates, L.L.C., the General Partner of Oak X Affiliates Fund, Limited Partnership</signatureName>
        <signatureDate>2004-05-12</signatureDate>
    </ownerSignature>
</ownershipDocument>

