Around 2:30 a.m., the victim walked into North Bay Medical Center and was treated for non-life threatening injuries, police said.
He apparently refused to give any information about his alleged attacker except the stabbing may have been around Pennsylvania Avenue and Kentucky Street.
Officers searched the area but did not find a crime scene, any witnesses or any suspects.
Anyone with information is asked to call the Fairfield Police Department at (707) 428-7300 or Crime Stoppers at (707) 644-STOP, which is (707) 644-7867.
Tips that lead to an arrest could be rewarded with up to $1,000.
