A case of massive intestinal bleeding from jejunal diverticulum is describe. A 62-year-old man was refered to our hospital because of melena and anemia. After admission, he showed massive hematochezia with unstable vital sign. Esophagogastroduodenocopy and colonoscopy, selective abdominal angiography, and RBC bleeding scanning were performed to seek the cause of the intestinal bleeding, but none of these studies revealed the source of bleeding. The examination of small bowel with methylcellulose showed multiple small jejunal diverticuli and a large diverticulum. Resection of the involved portion of jejunum was performed. On pathological examination, two mucosal loss lesions were detected, but ulcer or arteriovenous malformation were not seen in the resected jejunal diverticulum. The patient showed no more intestinal bleeding after operation. Although jejunal diverticuli are rare, the careful search for this complication in a patient with intestinal bleding is important.