Romney was the choice of 20 percent of all Republicans nationwide and Gingrich was favored by 19 percent, results of a Gallup-USA Today poll released Monday indicated.
Among GOP registered voters, Gingrich was at 22 percent and Romney at 21 percent.
Romney, the former Massachusetts governor, has been the leader or tied for the lead in nearly every poll conducted since May, Gallup said.
Support for Gingrich, a former House speaker, has risen in the last three polls after bottoming out at 4 percent in August, the Princeton, N.J., polling agency said.
Georgia businessman Herman Cain, dogged by allegations of sexual harassment, which he has denied, has seen his support dip from 21 percent to 16 percent.
Texas Gov. Rick Perry's support fell to 8 percent in the latest poll. Perry's support has slipped in each of the last three polls after peaking at 29 percent in August soon after he announced his bid.
Results are based on nationwide telephone interviews with 1,062 Republicans and Republican-leaning independents conducted Nov. 13-17. The margin of error is 4 percentage points.