INTRODUCTION: Melenic stools are typically indicative of gastrointestinal bleeding that may originate anywhere from the nares to cecum. Most common etiologies include gastritis, peptic ulcer disease, angioectasias, gastro-esophageal varices or malignant lesions. Here, we describe a rare case of melena caused by gastroduodenal artery (GDA) pseudoaneurysm with bleeding pancreatic necrosis and duodenal erosion. CASE DESCRIPTION/METHODS: A 58-year-old female with a history of class III obesity, chronic obstructive pulmonary disease, and recurrent pancreatitis presented with melenic stools, abdominal pain, and fatigue. Initial labs were significant for a hemoglobin of 6.0 g/dL. Computed Tomography (CT) of abdomen showed diffuse pancreatic necrosis with gas throughout the pancreas, which had progressed from imaging one month prior. Upper endoscopy was significant for erythematous duodenopathy but did not reveal any clear source of bleeding. Colonoscopy showed dark stool mixed with blood and hematin. In view of ongoing bleeding and transfusion requirements, push enteroscopy was performed showing a large blood clot and necrotic material in the duodenal bulb and second portion of the duodenum. Findings were concerning for erosion of pancreatic necrosis through the wall of the duodenum and erosion through a blood vessel resulting in active bleeding. Interventional radiology (IR) was consulted, and angiography demonstrated a GDA pseudoaneurysm which was successfully coil embolized. After the embolization, she was managed non-operatively due to her substantial co-morbid conditions. In total, she required 14 units of packed red blood cells during the hospitalization. Her bleeding resolved and she was discharged on high dose of oral proton pump inhibitors. DISCUSSION: Representing only 1.5% of visceral arterial aneurysms, GDA pseudoaneurysms very seldomly occur as a result of acute pancreatitis with necrosis. A history of recurrent pancreatitis is frequently noted. Pseudoaneurysm formation occurs due to pancreatic enzyme release and subsequent chronic inflammation, resulting in breakdown of the arterial wall and blood collection enclosed by adjacent fibrous tissue. Our case demonstrates an even rarer occurrence of erosion of the pancreatic necrosis through the wall of the duodenum, with active bleeding from the GDA pseudoaneurysm manifesting as severe gastrointestinal bleeding. Timely recognition is vital, as 40% of ruptured GDA pseudoaneurysms result in death. Management is completed through IR embolization or surgery.