The vote was a major victory for opponents who contend the measure would infringe on religious freedom and is not needed because the state already permits civil unions.
The 20-14 vote defeating the measure followed an hour and a half of public debate inside the packed Senate chamber. The nearly thousand supporters and opponents of the bill held rallies on the Statehouse steps.
The measure fell seven votes short of the 21 needed for passage.
Gay-rights advocates had pushed hard to get the bill passed before January 19, when Republican Chris Christie becomes governor. Democratic Gov. Jon Corzine promised to sign the bill if approved by the Legislature but Christie has said he would veto it.
The bill cleared the Judiciary Committee early last month by just one vote, but a vote by the chamber was delayed while supporters of the legislation sought additional support.
Today’s vote follows the same outcome last month in New York, where the state Senate voted down similar legislation to legalize same-sex marriage.
“Today’s vote by the New Jersey Senate perpetuates a system of inequality in the Garden State,” said HRC President Joe Solmonese. “Failing to provide loving, committed couples access to marriage leaves them separate and unequal – civil unions are not the same as marriage.”
More from the New Jersey Star-Ledger.