The Des Moines Register poll found 25 percent of likely GOP caucus-goers favor the former U.S. House speaker from Georgia compared with 18 percent who like U.S. Rep. Ron Paul of Texas and 16 percent who support former Massachusetts Gov. Mitt Romney.
U.S. Rep. Michele Bachmann of Minnesota and Georgia businessman Herman Cain, who suspended his campaign Saturday amid allegations he had a long-term extramarital affair and sexual harassment, were next at 8 percent each. Texas Gov. Rick Perry and former U.S. Sen. Rick Santorum of Pennsylvania each had 6 percent, and former Utah Gov. Jon Huntsman polled 2 percent support.
The newspaper said its poll of 401 likely caucus-goers was conducted Nov. 27-30 by Selzer & Co. of Des Moines and has a margin of error of plus or minus 4.9 percentage points.
Gingrich's support jumped up from 7 percent from the last Iowa Poll, conducted Oct. 23-26. Cain had been the leader in October with 23 percent support.
The poll indicates a still-fluid situation among likely caucus-goers with 11 percent uncommitted and 60 percent saying they could still be convinced to change their mind.
But it also found Gingrich is the most request second choice among those polled.
The Iowa caucuses on Jan. 3 will be the first step in the caucus and primary process of nominating a Republican candidate to run against Democratic President Barack Obama in next November's general election.