The annual competition is held at the Bridge Inn in the Lake District hamlet of Santon Bridge. Contestants have five minutes to impress the judges with a whopping but convincing lie.
Politicians and lawyers are barred from entry, as they are considered to have an unfair advantage.
Last year's winner was nuclear power plant worker Glen Boyland, for an improbable story about racing snails with Prince Charles.
The competition was founded in honor of 19th-century Bridge Inn landlord Will Ritson, who was renowned for his tall tales.
Thursday's event is sponsored by local brewer Jennings, which has produced a World's Biggest Liar ale to mark the event.