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

    <schemaVersion>X0201</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2004-04-02</periodOfReport>

    <issuer>
        <issuerCik>0001094286</issuerCik>
        <issuerName>WATER PIK TECHNOLOGIES INC</issuerName>
        <issuerTradingSymbol>PIK</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001224419</rptOwnerCik>
            <rptOwnerName>STREUFERT VICTOR C</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>23 CORPORATE PLAZA</rptOwnerStreet1>
            <rptOwnerStreet2>SUITE 246</rptOwnerStreet2>
            <rptOwnerCity>NEWPORT BEACH</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>92660</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>VP - Finance, CFO</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2004-04-02</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>J</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F2"/>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>20968</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>14.04</value>
                    <footnoteId id="F3"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>161816</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>15000</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By Trust</value>
                    <footnoteId id="F4"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">Non-Market transaction.</footnote>
        <footnote id="F2">Shares disposed of were originally purchased by the Reporting Person through loans from the Company pursuant to the terms of the Stock Acquisition and Retention Program (&quot;SARP&quot;) under the Water Pik Technologies, Inc. Employee Stock Purchase Plan.  In the transaction on 4/2/04, the disposed shares were tendered to the Company by the Reporting Person to repay a portion of one of such loans, as permitted by the terms of the SARP under the Water Pik Technologies, Inc. Employee Stock Purchase Plan. The transaction on 4/2/04 was planned pursuant to the terms of an SEC Rule 10b5-1 plan entered into between the Reporting Person and the Company on 2/12/04.</footnote>
        <footnote id="F3">Price determined by the average of the high and low trading prices on 4/1/04 according to the terms of the Stock Acquisition and Retention Program under Water Pik Technologies, Inc. Employee Stock Purchase Plan.</footnote>
        <footnote id="F4">The shares are held by The Streufert Family Revocable Living Trust, dated May 16, 1997, for the benefit of the Reporting Person and his spouse.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>Victor C. Streufert</signatureName>
        <signatureDate>2004-04-02</signatureDate>
    </ownerSignature>
</ownershipDocument>

