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

    <schemaVersion>X0303</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2008-09-09</periodOfReport>

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

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001189452</rptOwnerCik>
            <rptOwnerName>GRODMAN MARC</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>1</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>President, CEO</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2008-09-09</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>G</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>10000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>1407079</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>226667</value>
                    <footnoteId id="F2"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By wife and children</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Forward Contract (Right/Obligation to Sell)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <footnoteId id="F1"/>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2006-12-21</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>J</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>0</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <footnoteId id="F1"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F1"/>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F1"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <footnoteId id="F1"/>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>0</value>
                    <footnoteId id="F1"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">See Below.</footnote>
        <footnote id="F2">Includes 173,467 shares owned directly by Dr. Grodman's wife and 53,200 shares owned by their children. The reporting person disclaims beneficial ownership of these 226,667 shares.</footnote>
    </footnotes>

    <remarks>(1) On October 12, 2006, Marc D. Grodman established a Rule l0b-5-1 Sales Plan (the &quot;Sales Plan&quot;) with Bear Stearns &amp; Co., Inc. (&quot;Bear Stearns&quot;) to facilitate sales of a variable number of Dr. Grodman's shares of BRLI Common Stock (up to 200,000 shares) in variable pre-paid forward transactions (&quot;Forward Transactions&quot;) at a minimum per share sale price as specified in the Sales Plan. In connection with the contemplated Forward Transactions, Dr. Grodman pledged 200,000 shares of his BRLI Common Stock to secure his obligation to deliver a maximum aggregate 200,000 shares of Common Stock to Bear Stearns on the final settlement dates (varying from 23 to 25 months after each sale). The Sales Plan was terminated on December 21, 2006 at which date an aggregate 175,936 shares had been sold pursuant to the Forward Transactions. As prepayment for the pledge of these shares, Bear Stearns agreed to pay Dr. Grodman approximately $3,949,000 or approximately $22.45 per share. The number of shares that Dr. Grodman will be obligated to deliver on the final settlement dates will vary based upon the market prices of the Common Stock on such settlement dates. Dr. Grodman will benefit from any excess in the market prices of the Common Stock at the final settlement dates to the extent such prices exceed approximately $25.30 up to approximately $30.38 per share, by being able to deliver fewer shares. Until the final settlement dates, Dr. Grodman is deemed the beneficial owner of the pledged shares.</remarks>

    <ownerSignature>
        <signatureName>/s/ Roger Tolins - Attorney-in-Fact for Marc D. Grodman</signatureName>
        <signatureDate>2008-09-11</signatureDate>
    </ownerSignature>
</ownershipDocument>
