The poll found that 56 percent are against are against a legislative initiative to pass a constitutional amendment, while only 38 percent of voters are in favor of the measure — six percent were unsure.
Same-sex marriage has polarized the state since the Iowa Supreme Court unanimously ruled same-sex marriage legal in April 2009.
Since then, religious conservatives and Iowa Republican lawmakers have fought to put the issue before voters in hopes of overturning the court decision.
A bill was approved in the Republican-controlled Iowa House last year to authorize a statewide referendum, but Democratic leader Michael Gronstal has blocked it from consideration in the Senate.
With Gronstal blocking a Senate vote, a ballot initiative to ban same-sex marriage will likely not occur at least until 2014.
The latest poll shows little movement on the issue from February 2011, when 40 percent of those surveyed supported passing an amendment, while 54 percent were opposed.
Sen. Matt McCoy (D-Des Moines), the legislature’s only openly gay member, said he thinks “most Iowans recognize that this issue has very little to do with them and their lives, and it certainly doesn’t impact their marriages or the way they live their lives.”
“It is really more about allowing people to be able to commit to people they love,” McCoy said.