Of those interviewed for The Washington Post poll, 46 percent overall favored legal same-sex marriage while 44 percent opposed it and 10 percent had no opinion.
Maryland's move away from an overall clear majority opposition in past years to a nearly equal split now reflects a national trend, the Post reported Tuesday.
Among registered voters, 48 percent were in favor and 43 percent were opposed, with Democrats and independents largely favoring legal same-sex marriage while 69 percent of Republicans opposed it, the poll suggested.
Fifty-five percent of those polled said gay men and women legally married in another state should have the marriages recognized in Maryland -- a position taken by Democratic state Attorney General Douglas Gansler.
In February, Gansler told state agencies to begin granting married same-sex couples from other states the same rights as Maryland's heterosexual couples.