Anisakiasis is a parasitic disease following eating raw fishes infected with Anisakis larvae. The endoscopic features of the gastric mucosa are edema, erosion, ulceration and hemorrhage. Gastric anisakiasis forming submucosal tumor is rare. Twenty six-year-old man who complained of severe epigastric pain was admitted. The pain began approximately three hours after eating slices of raw Astroconger myriaster. Gastric endoscopy revealed a submucosal tumor with central erosion on the gastric fundus. Endoscopic ultrasonography detected a thickening of the gastric wall made of mainly thickened submucosal layer. Abdominal CT scan showed a gastric mass lesion with hypodensity in the gastric fundus and subsequently wedge resection was performed. The pathologic finding of the resected mass was eosinophilic abscess in the submucosal layer. We report a case of gastric submucosal tumor which seems to be caused by Anisakis, with a review of relevant literature. (Korean J Gastrointest Endosc 2003;27:2630)