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

    <schemaVersion>X0203</schemaVersion>

    <documentType>3</documentType>

    <periodOfReport>2011-06-20</periodOfReport>

    <noSecuritiesOwned>0</noSecuritiesOwned>

    <issuer>
        <issuerCik>0001093430</issuerCik>
        <issuerName>CASPIAN SERVICES INC</issuerName>
        <issuerTradingSymbol>CSSV</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001272232</rptOwnerCik>
            <rptOwnerName>BAISEITOV BAKHYTBEK R</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>291/21 DOSKYK AVE</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>ALMATY</rptOwnerCity>
            <rptOwnerState>1P</rptOwnerState>
            <rptOwnerZipCode>050020</rptOwnerZipCode>
            <rptOwnerStateDescription>KAZAKSTAN</rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <valueOwnedFollowingTransaction>
                    <value>9398334</value>
                    <footnoteId id="F1"/>
                </valueOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes>
        <footnote id="F1">All shares underlie convertible debt pursuant to a Facility Agreement originally entered into between the Issuer and Altima Central Asia Master (Fund) Ltd. on 20 June 2008.  The Facility Agreement has been assigned to and the Reporting Person completed the acquisition of the convertible debt as of the transaction date.  The number of shares underlying the convertible debt was determined as of the transaction date.  The debt is convertible at a fixed price of $2.30 per share. The number of shares issuable upon conversion will increase as interest continues to accrue.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ Bakhytbek Baiseitov</signatureName>
        <signatureDate>2011-06-27</signatureDate>
    </ownerSignature>
</ownershipDocument>
