"I will take full responsibility for the failure of this campaign to gain traction," Hunter said in a speech to campaign volunteers, friends and curious onlookers.
Hunter acknowledged that his run never gained popular momentum but he felt he scored a political victory in forcing other campaigns to take on issues he championed - border security, the burgeoning economic threat of China and the need to rebuild America's military.
"The other candidates today are talking about things I brought up," he said, alongside his wife, Lynne, and their two sons. "So I think that in itself is a great victory for this campaign."
The decision to withdraw comes after a poor showing in the Nevada caucuses.
"We thought we'd do much better in Nevada, but the numbers weren't there," said campaign spokesman Bob Bevill. "We were not able to get any traction."
Hunter, a San Diego-area congressman, spent most of Saturday in Nevada.
In recent weeks he was forced at every stop to dispel rumors that the campaign was already dead and was unable to talk about the issues, Bevill said. The best showing of Hunter's campaign was in Wyoming's Jan. 5 caucuses, in which he won 8 percent of the vote, finishing third behindand .
"The media has a 'vote someone off the island' mentality and Duncan Hunter was a casualty of that," said Bevill.
Hunter, a Vietnam veteran, was elected to Congress in 1980 as part of President Reagan's sweep into power. He appealed to some conservatives by focusing on military issues and border security.