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

    <schemaVersion>X0202</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2005-09-28</periodOfReport>

    <issuer>
        <issuerCik>0000792641</issuerCik>
        <issuerName>BIO REFERENCE LABORATORIES INC</issuerName>
        <issuerTradingSymbol>BRLI</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001189454</rptOwnerCik>
            <rptOwnerName>DUBINETT HOWARD</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>481 EDWARD H. ROSS DRIVE</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>ELMWOOD PARK</rptOwnerCity>
            <rptOwnerState>NJ</rptOwnerState>
            <rptOwnerZipCode>07407</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>Executive VP, COO</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>481001</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                    <footnoteId id="F1"/>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <derivativeTable>
        <derivativeHolding>
            <securityTitle>
                <value>Stock Option (right to buy)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>6.80</value>
            </conversionOrExercisePrice>
            <exerciseDate>
                <value>2002-01-16</value>
            </exerciseDate>
            <expirationDate>
                <value>2007-01-16</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>4000</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>4000</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeHolding>
        <derivativeTransaction>
            <securityTitle>
                <value>Forward Contract (Right/Obligation to Sell)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <footnoteId id="F2"/>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2004-03-30</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>J</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>0</value>
                    <footnoteId id="F2"/>
                </transactionShares>
                <transactionPricePerShare>
                    <footnoteId id="F2"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F2"/>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F2"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <footnoteId id="F2"/>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>0</value>
                    <footnoteId id="F2"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeTransaction>
        <derivativeTransaction>
            <securityTitle>
                <value>Forward Contract (Right/Obligation to Sell)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <footnoteId id="F3"/>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2005-09-28</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>J</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>0</value>
                    <footnoteId id="F3"/>
                </transactionShares>
                <transactionPricePerShare>
                    <footnoteId id="F3"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F3"/>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F3"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <footnoteId id="F3"/>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>0</value>
                    <footnoteId id="F3"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">Includes 477,001 shares owned directly and 4,000 shares issuable upon exercise of options.</footnote>
        <footnote id="F2">In lieu of an outright sale, on March 30, 2004, Howard Dubinett entered into a pre-paid variable forward sales contract (&quot;Forward Contract&quot;) with Bear Stearns Bank plc (&quot;Bear Stearns&quot;). Pursuant to the Forward Contract, Mr. Dubinett pledged 100,000 shares of his BRLI Common Stock to secure his obligation to deliver a maximum 100,000 shares of BRLI Common Stock to Bear Stearns on March 30, 2006 (the &quot;Settlement Date&quot;). As prepayment for the pledge of these shares, Bear Stearns paid Mr. Dubinett $1,297,680 or approximately $12.98 per share representing 80.75% of the proceeds from the sale of 100,000 shares on March 30, 31 and April 1, 2004. The shares that Mr. Dubinett will be obligated to deliver on the Settlement Date varies based on the price of the Common Stock on the Settlement Date. Mr. Dubinett will benefit from any excess in the price of the Common Stock on the Settlement Date between $16.07 per share up to a maximum $21.69 per share by being able to deliver fewer shares.</footnote>
        <footnote id="F3">In lieu of an outright sale, on September 28, 2005, Howard Dubinett entered into a pre-paid variable forward sales contract (&quot;Forward Contract&quot;) with Bear Stearns Bank plc (&quot;Bear Stearns&quot;). Pursuant to the Forward Contract, Mr. Dubinett pledged 100,000 shares of his BRLI Common Stock to secure his obligation to deliver a maximum 100,000 shares of BRLI Common Stock to Bear Stearns on September 28, 2007 (the &quot;Settlement Date&quot;). As prepayment for the pledge of these shares, Bear Stearns paid Mr. Dubinett $1,374,400 or approximately $13.74 per share representing 80% of the proceeds from the sale of 100,000 shares on September 28, 2005. The shares that Mr. Dubinett will be obligated to deliver on the Settlement Date varies based on the price of the Common Stock on the Settlement Date. Mr. Dubinett will benefit from any excess in the price of the Common Stock on the Settlement Date between $17.18 per share up to a maximum $24.052 per share by being able to deliver fewer shares.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ Roger Tolins - Attorney-in-Fact for Howard Dubinett</signatureName>
        <signatureDate>2005-09-29</signatureDate>
    </ownerSignature>
</ownershipDocument>
