We report a case of gastrointestinal stromal tumor of the stomach 17 years after pancreatoduodenectomy(PD). The patient was an 83-year-old man who had undergone PD for chronic pancreatitis at 65 years of age. Gastric endoscopy revealed a 2.5-cm gastric submucosal tumor on the lesser curvature of the stomach, which was the gastrojejunostomy site. As the gross appearance of the tumor showed ulceration at the top of the tumor, the patient underwent total gastrectomy and Roux-en-Y reconstruction. Histopathological examination demonstrated that the tumor was a GIST of the stomach. Currently, 5 years after surgery, no recurrence has been observed. Therefore, postsurgical care for a malignant disease may require a strict follow-up for a long time.