With 96 percent of Republican precincts reporting late Thursday, Huckabee led the field with 34 percent of the vote, to 25 percent for former Massachusetts Gov. Mitt Romney, The Des Moines Register reported, even though Romney's campaign vastly outspent the Huckabee campaign in the state.
Arizona Sen. John McCain and former Tennessee Sen. Fred Thompson were tied for fourth with 13 percent each and Texas Rep. Ron Paul had 10 percent. Former New York Mayor Rudy Giuliani, who scarcely campaigned in Iowa, garnered just four percent in Thursday's caucuses.
Entrance polls showed Huckabee gaining overwhelming support among evangelicals and women, CNN said.
Conceding defeat Thursday, Romney suggested his fortunes would turn next Tuesday in New Hampshire's first-in-the-nation 2008 presidential primary. McCain was in New Hampshire rather than Iowa during the caucuses Thursday.
Romney and McCain are tied for first place in New Hampshire in a CNN poll released Thursday.