The former Massachusetts governor drew 45 percent support to the former House speaker's 25 percent heading into Saturday's caucuses, according to the statewide survey commissioned by the Las Vegas Review-Journal and KLAS-TV 8NewsNow.
Former Pennsylvania Sen. Rick Santorum drew 11 percent support and Texas Congressman Ron Paul drew 9 percent, with 10 percent of respondents saying they were undecided or wanted another candidate.
The poll by the Cannon Survey Center at the University of Nevada, Las Vegas had a margin of sampling error of plus or minus 4.75 percentage points.
Pollsters questioned 426 Republicans by home and cellular phones Friday through Tuesday, the day Romney won the Florida primary over Gingrich.
Republican delegates in Nevada's fifth-in-the-nation presidential nominating contest will be awarded proportionally by the percentage of the caucus vote each candidate gets.
Organizers project more caucus-goers this year than in 2008 when about 44,000 Republicans turned out.
President Barack Obama was the sole nominee for Nevada Democrats when they held their caucus on Jan. 21.