<SEC-DOCUMENT>0001179110-17-002243.txt : 20170213
<SEC-HEADER>0001179110-17-002243.hdr.sgml : 20170213
<ACCEPTANCE-DATETIME>20170213162221
ACCESSION NUMBER:		0001179110-17-002243
CONFORMED SUBMISSION TYPE:	5
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20161231
FILED AS OF DATE:		20170213
DATE AS OF CHANGE:		20170213

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			ALEXANDERS INC
		CENTRAL INDEX KEY:			0000003499
		STANDARD INDUSTRIAL CLASSIFICATION:	REAL ESTATE INVESTMENT TRUSTS [6798]
		IRS NUMBER:				510100517
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		210 ROUTE 4 EAST
		CITY:			PARAMUS
		STATE:			NJ
		ZIP:			07652
		BUSINESS PHONE:		201-587-8541

	MAIL ADDRESS:	
		STREET 1:		210 ROUTE 4 EAST
		CITY:			PARAMUS
		STATE:			NJ
		ZIP:			07652

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			MACNOW JOSEPH
		CENTRAL INDEX KEY:			0001246482

	FILING VALUES:
		FORM TYPE:		5
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-06064
		FILM NUMBER:		17599466
</SEC-HEADER>
<DOCUMENT>
<TYPE>5
<SEQUENCE>1
<FILENAME>edgar.xml
<DESCRIPTION>FORM 5 -
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0306</schemaVersion>

    <documentType>5</documentType>

    <periodOfReport>2016-12-31</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <form3HoldingsReported>0</form3HoldingsReported>

    <form4TransactionsReported>0</form4TransactionsReported>

    <issuer>
        <issuerCik>0000003499</issuerCik>
        <issuerName>ALEXANDERS INC</issuerName>
        <issuerTradingSymbol>ALX</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001246482</rptOwnerCik>
            <rptOwnerName>MACNOW JOSEPH</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>210 ROUTE 4 EAST</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>PARAMUS</rptOwnerCity>
            <rptOwnerState>NJ</rptOwnerState>
            <rptOwnerZipCode>07652</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>EVP - Finance, Chief Admin. Of</officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>4586</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>held by spouse</value>
                    <footnoteId id="F1"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes>
        <footnote id="F1">This Common Stock is held by Mr. Macnow's spouse.  The filing of this Form 5 shall not be deemed an admission that Mr. Macnow is the beneficial owner of this Common Stock.  This Common Stock was gifted to Mr. Macnow's spouse and previously reported as individually held.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ Steven Santora, Attorney in Fact</signatureName>
        <signatureDate>2017-02-13</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
