We report a case of gastrojejunal fistula caused by benign gastric ulcer, a very rare condition. The patient was an 81-year-old-woman who had had multiple recurrences of gastric ulcer. She also had diabetes mellitus. She was admitted to our hospital because of a left femoral head fracture, necessitating a mechanical bone head exchange operation. She had severe abdominal pain and anemia on the 48th postoperative day. Gastroendoscopic examination revealed a giant ulcer with a long-axis diameter of more than 5cm on the lesser curvature of the gastric body. She was treated with intravenous famotidine and all oral intake was restricted; her symptoms were alleviated. Two weeks later, a fistula had formed between the stomach and the jejunum just anal to the duodeno-jejunal flexure. She was placed on an ulcer diet, and was discharged with no symptoms on the 151st postoperative day. She has remained asymptomatic for 1 1/2, years to date. Lack of H2-antagonist administration, operative stress, and administration of ipriflavone appeared to have induced gastric ulcer recurrence, and formation of the fistula between the stomach and the jejunum seemed to have been facilitated by the patient being very lean and having minimal mesenteric adipose tissue.