Introduction: Diverticula can develop anywhere along the small bowel, most commonly in the duodenum. While most patients with duodenal diverticula are asymptomatic, some develop complications such as obstruction, diverticulitis, obstructive jaundice, and bleeding. Here, we present a unique manifestation of bleeding within a periampullary diverticulum. Case Description/Methods: A 66-year-old male with a history of hypertension, diabetes mellitus, end-stage renal disease, atrial fibrillation, and recent four-vessel coronary artery bypass grafting (CABG) presented with unstable angina and fatigue. Following his CABG 2 months ago, he was placed on warfarin and aspirin. His exam revealed hypotension, conjunctival pallor, active bowel sounds, and melena. His hemoglobin (Hb) was 5 g/dL compared to a baseline of 9.2 g/dL two months prior. Blood urea nitrogen was 154 mg/dL and creatinine was 3.47 mg/dL, elevated from his baseline. INR was 6.9 and troponin-I was 66.9 ng/mL. An electrocardiogram did not show ST-segment elevation. After medical management of his myocardial infarction, an upper endoscopy was only remarkable for a large periampullary diverticulum (PAD) containing a clot. Over the next 3 days, his Hb continued to downtrend despite transfusion. A repeat endoscopy showed blood in the gastric body and antrum, blood clots in the duodenal bulb, and oozing blood from the diverticulum. At this time, a side-viewing scope was utilized for better visualization and showed a large pantaloon diverticulum straddling a ridge overlying the common bile duct (CBD) with an ulcer and visible vessel (Figure 1). Hemostatic clip placement led to the cessation of the bleed. (Figure 2). His hemodynamics stabilized and he was maintained on twice-daily pantoprazole. There was a transient rise in his AST and ALT, which resolved spontaneously. The patient did not re-bleed. Discussion: Our patient had an ulcer within a pantaloon PAD that was only appreciated with a side-viewing duodenoscope. Thus, if there is any suspicion of blood within a large duodenal diverticulum such as a clot, the use of a side-viewing scope is warranted. Furthermore, treatment of this lesion was challenging as the ridge overlayed the CBD, raising concern for injuring the CBD or causing obstruction through endoclips or cautery, so the former was employed taking care not to grasp excess tissue other than the visible vessel. While the transient rise in the transaminases suggested a CBD obstruction, this was short-lived and no clinical sequelae ensued.