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

    <schemaVersion>X0202</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2007-05-12</periodOfReport>

    <issuer>
        <issuerCik>0001142750</issuerCik>
        <issuerName>AMN HEALTHCARE SERVICES INC</issuerName>
        <issuerTradingSymbol>AHS</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001320242</rptOwnerCik>
            <rptOwnerName>Jackson Denise L</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>12400 HIGH BLUFF DRIVE</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>SAN DIEGO</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>92130</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>General Counsel/Sr. VP</officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2007-05-12</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>M</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>3741</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>22.62</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>3741</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
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            <transactionDate>
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            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>F</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F1"/>
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            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>1337</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>22.62</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
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                </transactionAcquiredDisposedCode>
            </transactionAmounts>
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                    <value>2404</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
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                    <value>D</value>
                </directOrIndirectOwnership>
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    </nonDerivativeTable>

    <derivativeTable>
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            <conversionOrExercisePrice>
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            <exerciseDate>
                <footnoteId id="F3"/>
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            <expirationDate>
                <value>2017-04-18</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
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                </underlyingSecurityShares>
            </underlyingSecurity>
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                </sharesOwnedFollowingTransaction>
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            <ownershipNature>
                <directOrIndirectOwnership>
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                </directOrIndirectOwnership>
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            </transactionTimeliness>
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                </transactionShares>
                <transactionPricePerShare>
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            <exerciseDate>
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            <expirationDate>
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            <underlyingSecurity>
                <underlyingSecurityTitle>
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                </underlyingSecurityTitle>
                <underlyingSecurityShares>
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                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
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                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
        <derivativeHolding>
            <securityTitle>
                <value>Stock Appreciation Rights</value>
            </securityTitle>
            <conversionOrExercisePrice>
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            <exerciseDate>
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            <expirationDate>
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            </expirationDate>
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                <underlyingSecurityTitle>
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                </underlyingSecurityTitle>
                <underlyingSecurityShares>
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                </underlyingSecurityShares>
            </underlyingSecurity>
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            <ownershipNature>
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                    <value>D</value>
                </directOrIndirectOwnership>
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        <derivativeHolding>
            <securityTitle>
                <value>Stock Appreciation Rights</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>24.95</value>
            </conversionOrExercisePrice>
            <exerciseDate>
                <footnoteId id="F6"/>
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            <expirationDate>
                <value>2017-04-18</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>12398</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>12398</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeHolding>
        <derivativeHolding>
            <securityTitle>
                <value>Stock Options (Right to buy)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>9.68</value>
            </conversionOrExercisePrice>
            <exerciseDate>
                <value>2004-05-08</value>
            </exerciseDate>
            <expirationDate>
                <value>2013-05-08</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>7500</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>7500</value>
                    <footnoteId id="F7"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeHolding>
        <derivativeHolding>
            <securityTitle>
                <value>Stock Options (Right to buy)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>14.86</value>
            </conversionOrExercisePrice>
            <exerciseDate>
                <value>2006-05-04</value>
            </exerciseDate>
            <expirationDate>
                <value>2015-05-04</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>65000</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>65000</value>
                    <footnoteId id="F7"/>
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            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
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        </derivativeHolding>
        <derivativeHolding>
            <securityTitle>
                <value>Stock Options (Right to buy)</value>
            </securityTitle>
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                <value>14.94</value>
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            <exerciseDate>
                <value>2005-05-18</value>
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            <expirationDate>
                <value>2014-05-18</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>27500</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>27500</value>
                    <footnoteId id="F7"/>
                </sharesOwnedFollowingTransaction>
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            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeHolding>
        <derivativeHolding>
            <securityTitle>
                <value>Stock Options (Right to buy)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>22.98</value>
            </conversionOrExercisePrice>
            <exerciseDate>
                <value>2003-01-17</value>
            </exerciseDate>
            <expirationDate>
                <value>2012-01-17</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>11000</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>11000</value>
                    <footnoteId id="F7"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeHolding>
    </derivativeTable>

    <footnotes>
        <footnote id="F7">The options to purchase shares of Common Stock were granted pursuant to the AMN Healthcare Services, Inc. Stock Option Plan.  The shares vest in four equal installments on the first, second, third and fourth anniversary of the grant date.</footnote>
        <footnote id="F3">The Restricted Stock Units vest on April 18, 2010, provided, however, the Restricted Stock Units shall vest on an accelerated basis on May 18, 2008, in the incremental amount of 33% should the Company achieve or exceed specified earnings before interest, taxes, depreciation and amortization (EBITDA) targets for fiscal year 2007 and on April 18, 2009, in the amount of 34% should the Company achieve or exceed EBITDA targets and that such Restricted Stock Units shall have a term of ten years unless earlier terminated in accordance with the Plan or the applicable Restricted Stock Units agreement. The settlement date of the Restricted Stock Units shall be the vesting date unless the grantee otherwise elects under the terms of the Company's 2005 Amended and Restated Executive Nonqualified Excess Plan.</footnote>
        <footnote id="F5">The Restricted Stock Units vest on April 12, 2009, provided, however, the Restricted Stock units shall vest on an accelerated basis on May 12, 2007, in the incremental amount of 33% should the Company achieve or exceed specified earnings before interest, taxes, depreciation and amortization (EBITDA) targets for fiscal year 2006 and on April 12, 2008, in the amount of 34% should the Company achieve or exceed specified EBITDA targets and that such Restricted Stock Units shall have a term of ten years unless earlier terminated in accordance with the Plan or the applicable Restricted Stock Units Agreement.  The settlement date of the Restricted Stock Units shall be the vesting date unless the grantee otherwise elects under the terms of the Company's 2005 Amended and Restated Executive Nonqualified Excess Plan.</footnote>
        <footnote id="F6">The Stock Appreciation Rights were granted pursuant to the AMN Healthcare Equity Plan.  The Stock Appreciation Rights vest over three years on the anniversary of the date of the grant in increments of 33%, 34% and 33% respectively.</footnote>
        <footnote id="F1">Number of shares withheld for tax purposes.</footnote>
        <footnote id="F4">Common Stock acquired on the vesting of Restricted Stock Units.</footnote>
        <footnote id="F2">The Restricted Stock Units were granted pursuant to the AMN Healthcare Equity Plan.  Each Restricted Stock Unit represents a contingent right to receive one share of Common Stock.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>Denise L. Jackson</signatureName>
        <signatureDate>2007-05-15</signatureDate>
    </ownerSignature>
</ownershipDocument>
