A 76-year-old man who had been treated for ureteral stones and urinary tract infection in a local hospital was urgently transferred to our institution because his general condition became worse due to septic shock and multiple organ failure. On the 9th hospital day, a tarry stool was observed. Upper gastrointestinal endoscopy showed gastric ulcer without active bleeding. On the eleventh day, he went into hemorrhagic shock due to massive blood loss, and a colonoscopy was performed. Despite the presence of an ulcerous lesion at the terminal ileum, any site of active bleeding could not be identified. No extravasation could be detected by an enhanced CT scan. After that, intermittent bleeding continued, and he went into a state of shock again on the 14th hospital day Emergency surgery was thus performed. Operative findings showed no obvious abnormalities on the serosal side of the small intestine. When an endoscope was inserted from the incision site of the terminal end of the ileum, arterial hemorrhage was observed in the intestinal wall 110 cm proximal from the incision, and it was treated with coagulation. There was no apparent ulceration at the lesion, suggesting a Dieulafoy's ulcer. One year after the operation, no rebleeding occurred, and the colostomy was closed.