Anisakiasis is an acute gastrointestinal disease caused by infection with the larval stages of herring worm (Anisakis spp.) or the cod worm (Pseudoterranova decipiens). Humans can be accidental hosts by consuming raw or undercooked fish. Anisakiasis occurs throughout the world, with foci in north Asia and western Europe. After ingestion, larvae penetrate the gastrointestinal mucosa and there is severe abdominal pain, with nausea and vomiting. Some patients develop syndromes exhibiting clinical manifestations of allergy.