Lemmel syndrome is an uncommon pancreaticobiliary consequence of duodenal diverticula. We herein present a case of an 80-year-old male who presented with upper abdominal discomfort. Based on lab values and relevant clinical history, a diagnosis of obstructive jaundice was made. A contrast-enhanced CT scan of the abdomen revealed gross dilatation of intra-hepatic and extra-hepatic bile duct, cystic duct, common bile duct, major and minor pancreatic duct. A contrast-filled outpouching was seen from the medial wall of the second part of the duodenum with duodenal diverticulum and papilla within it. The abrupt termination of the common bile duct and main pancreatic duct adjacent to the thickened wall of the diverticulum was the cause of the patient's pancreaticobiliary obstruction. In the absence of cholelithiasis or tumor, the duodenal diverticulum that manifests as obstructive jaundice is known as Lemmel syndrome. Prompt identification of Lemmel syndrome can avoid dangerous complications and unnecessary investigations. Gallstones, cholangitis, and bile duct stones are more common in patients with duodenal diverticula. Treatment depends on patient presentation and may involve conservative management, surgical procedures in the form of excision of the diverticulum, or even endoscopic sphincterotomy or stenting.