Diverticulosis is a condition which balloon-like sacs developing in the intestinal wall commonly in the colon. Even though diverticulosis is usually asymptomatic, rare complications are the abdominal pain, infection, perforation, bleeding and intestinal obstruction. Colonoscopy and barium enema X-ray studies can confirm the diagnosis. It is rare to find diverticulosis in the small intestine. Bleeding is usually mild because diverticulum is usually formed at the antimesenteric border. When a diverticulum develops in mesenteric border, ulceration of its mucosa can erode into mesenteric blood vessels and may lead to massive bleeding. A 54-year-old male who was suffering from diabetes mellitus, hypertension and ischemic heart diseases developed abdominal pain and bleeding perrectum. Flexible sigmoidoscopy showed inflamed patches of bowel and upper gastrointestinal endoscopy revealed gastric erosions. Rectal bleeding persisted and the patient needed a transfusion of 25 pints of blood. CT angiogram revealed bleeding focus at the region of duodeno-jejunal junction. The patient died while he was getting transferred for Digital Subtraction Angiography. Postmortem examination showed external and internal pallor, mild pulmonary oedema and three sites of U- shaped bowel adhesions in the jejunum. All three loops had small pouches which opened into the intestinal lumen. One pouch which was present at the mesenteric border of the jejunum had an ulcer eroded into mesenteric blood vessels. This case is a very rare example of jejunal diverticulosis on mesenteric border causing fatal haemorrhage. When there is a history of massive rectal bleeding, small bowel diverticulosis is also should be considered in clinical practice as well as in forensic pathology practice.