Background Jejunal diverticulosis has an incidence of 1-2% per annum. (1) It is often diagnosed post-mortem or incidentally on imaging. As such, jejunal diverticulitis is a rare cause for abdominal pain, often resulting in delayed diagnosis with complications at presentation. Cases of perforated jejunal diverticulitis have a mortality rate as high as 40%.(2) Case 69-year-old male presents with acute onset, severe left upper quadrant pain on a background of three weeks of dark bowel motions. His vital signs were normal and on examination he had localised peritonism in the left upper quadrant. Admission bloods showed a mildly raised white cell count but normal biochemistry. CT scan that showed surrounding inflammation to a jejunal diverticulum and tracking free air within the central mesentery. He was imminently taken for laparotomy, wash out and small bowel resection. Intra-operative findings were mesenteric crepitus adjacent to the perforated jejunal diverticulum with surrounding fibrin. Purulent fluid found in left lower quadrant requiring wash out. Histology confirmed perforated jejunal diverticulitis with surrounding inflammatory change. Post-operatively, he progressed well and discharged day 4 post op. Discussion Jejunal diverticulitis is a rare entity, with vague symptoms, and as such can result in delayed diagnosis, leading to dangerous sequelae such as perforation. Contrary to colorectal diverticulosis, which forms adjacent to the anti-mesenteric taeniae, jejunal diverticulae form on the mesenteric side of the jejunum. As such, when they perforatem they often perforate into the mesentery. While there is no consensus regarding optimal treatment strategy, this case adds weight to the success of managing perforated jejunal diverticulitis aggressively with surgery.