The Assembly voted 42-33 in favor of the bill, which was approved in the state Senate Monday on a 24-16 vote.
All Assembly Republicans in attendance voted against the bill, The (Newark) Star-Ledger reported.
Senate President Stephen Sweeney said the Assembly Thursday took "the next step in establishing fair and equal rights in New Jersey."
"Marriage equality will happen in New Jersey," Sweeney said in a statement. "The only question that remains is whether Governor Christie will be on the right or wrong side of history."
Christie has said he prefers to put the issue before New Jersey voters in a referendum.
Assemblyman Jay Webber, a Republican, voted against the legislation.
"The bill is about redefining an important institution of civil society and that should give us all great pause," Webber said.
He argued during the Assembly debate that "desires" of gays and lesbians should not be permitted to "redefine marriage for everyone else."