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

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2015-12-31</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001029800</issuerCik>
        <issuerName>URSTADT BIDDLE PROPERTIES INC</issuerName>
        <issuerTradingSymbol>UBP</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001070094</rptOwnerCik>
            <rptOwnerName>BIDDLE WILLING L</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>53 ELMWOOD ROAD</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>SOUTH SALEM</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10590</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>President and CEO</officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2015-12-31</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>J</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F1"/>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>392</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>2700996</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See footnote</value>
                    <footnoteId id="F5"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2015-12-31</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>J</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F1"/>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>392</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>2701388</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See footnote</value>
                    <footnoteId id="F5"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2016-01-04</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>J</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F2"/>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>100000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>2801388</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See footnote</value>
                    <footnoteId id="F5"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2016-01-04</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>J</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F3"/>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>1050</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>2802438</value>
                    <footnoteId id="F4"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See footnote</value>
                    <footnoteId id="F5"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes>
        <footnote id="F1">On December 31, 2015, the Trust Established Under the Urstadt Biddle Properties Inc. Excess Benefit and Deferred Compensation Plan of 2005 (&quot;Compensation Plan Trust&quot;) made a required distribution of 392 shares of Common Stock to Willing L. Biddle (the &quot;Reporting Person&quot;), a participant in the Issuer's Deferred Compensation Plan.  This resulted in no change in the number of shares beneficially owned by the Reporting Person.</footnote>
        <footnote id="F2">On January 4, 2016, the Issuer entered into an agreement with the Reporting Person whereby the Reporting Person was granted a restricted stock award of 100,000 shares of Common Stock pursuant to the Issuer's Amended and Restated Restricted Stock Award Plan (the &quot;Restricted Stock Award Plan&quot;).</footnote>
        <footnote id="F3">On January 4, 2016 the Issuer entered into an agreement with Catherine U. Biddle, the Reporting Person's wife and a director of the Issuer, whereby Mrs. Biddle was granted a restricted stock award of 1,050 shares of Common Stock pursuant to the Restricted Stock Award Plan.</footnote>
        <footnote id="F4">This figure includes 950,000 restricted shares of Common Stock issued to Mr. Biddle and 3,050 restricted shares of Common Stock issued to Mrs. Biddle pursuant to the Restricted Stock Award Plan. On January 3, 2016, restrictions applicable to a previously reported grant to Mr. Biddle of 100,000 restricted shares of Common Stock lapsed, resulting in the Reporting Person becoming fully vested in such shares. This resulted in no change in the number of shares beneficially owned by the Reporting Person.</footnote>
        <footnote id="F5">After all transactions reported on this Form 4, Mr. Biddle is the direct beneficial owner of 2,191,785 shares of Common Stock, including the 953,050 restricted shares noted in Footnote 4. He is the indirect beneficial owner of 610,653 shares of Common Stock held as follows: 284,240 shares by each of the Willing L. Biddle Dynasty Trust (&quot;WLB Trust&quot;) and the Catherine U. Biddle Dynasty Trust (&quot;CUB Trust&quot;), of which the issue of Mr. and Mrs. Biddle are the beneficiaries and Mrs. Biddle and Mr. Biddle, respectively, are the trustees, 2,371 shares by the Compensation Plan Trust, 2,307 shares by Mr. Biddle's IRA, 5,163 shares by the P.T. Biddle (Dec'd) IRA for benefit of Mr. Biddle, 30,707 shares by Mrs. Biddle, 555 shares by her IRA, and 1,070 shares by the Chas. and Phoebe Biddle Trust for benefit of the Issue of Mr. Biddle (the &quot;Biddle Trust&quot;). Mr. Biddle and C. J. Urstadt are sole trustees of the Biddle Trust. Mr. Biddle disclaims beneficial ownership of shares held by the CUB Trust.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>Willing L. Biddle by Thomas D. Myers as Attorney-in-Fact</signatureName>
        <signatureDate>2016-01-05</signatureDate>
    </ownerSignature>
</ownershipDocument>
