The poll also found 55 percent in favor of allowing civil unions for gay people.
A majority — 54 percent — said they opposed a constitutional ban on gay marriage, an idea that has been repeatedly pushed by Republican legislators. Only 38 percent favored an amendment.
"There are more Republicans who would like to see it in the constitution," Ball State political scientist Joe Losco told WISH-TV. "But Democrats and independents are strongly against it."
The measure was approved by lawmakers last year and could come up for a vote again next year. If approved twice, it would go before voters in 2014.
Republican House Speaker Brian Bosma said at a legislative conference Thursday that he expects the amendment to be introduced again during the session that begins next month.
"There have been some who have suggested that we should wait to see what happens there before taking action. I'm not certain that's advisable at this point, but it's certainly under consideration," he said.
"Will it be a priority? No. Will it be addressed? Just like any other idea of the 1,500 ideas that will be addressed this year, I'm sure there will be discussion about whether they should proceed," he added.
But action from the U.S. Supreme Court, which announced this month it would take up a pair of cases on the broader issues, could make any action in the states moot.
Ryan England, a 31-year-old Indianapolis man who wants to marry his partner, 29-year-old Ben Snyder, said he didn't understand why state legislators would even discuss the idea at this point.
"It seems like they should have better things to do, and this is making its way through the legal system as it is," England told The Indianapolis Star.
Gov. Mitch Daniels said Wednesday he has been hearing from companies that fear gay marriage amendment in Indiana might also prevent firms from offering benefits to gay couples.
Indiana law already limits marriage to between one man and one woman, but supporters say they want the ban put into the state constitution so it can't be overturned by judges.
"I think that's good public policy," Curt Smith of the Indiana Family Institute told WISH. "And so do the authors of the amendment and, again, we've had strong votes in both houses of the Legislature and if this goes on the ballot I'm confident we'll get a strong vote from Hoosier voters."
The random statewide phone survey of 602 Hoosier adults was conducted Nov. 12-24 by the Princeton Survey Research Associates International. It has a margin of error of plus or minus 4.5 percentage points.