We report abdominal bleeding caused by arteriovenous malformations (AVM) of the posterior gastric artery. A 38-year-old man visited our hospital complaining of epigastralgia. Enhanced abdominal CT revealed a high density spot in a huge low density mass. Angiographic study showed AVM of the posterior gastric artery. Transcatheter arterial embolization was performed and we successfully treated the AVM which was accompanied by abdominal bleeding.