Anisakiasis of the gastrointestinal tract is caused by the ingestion of raw fish or uncooked food infested with Anisakis larvae. A large number of cases of gastric anisakiasis have been reported in countries where the eating of raw fish is customary. However, there have been few reports of anisakiasis of the colon confirmed by colonoscopy and also very few reports of endoscopic ultrasonographic findings of anisakiasis. A 47-year-old man had epigastric pain with nausea after eating raw anchovies. Endoscopy found a living tubular structure penetrating into the lesser curvature of the stomach and the midtranseverse colon area. It was withdrawn with biopsy forceps. We report a case of anisakiasis simultaneously invading the stomach and the colon confirmed by endosopic utrasonographic findings and biopsy findings.