Heterotopic pancreas, a developmental anomaly uncommonly noted both during operations and autopsies, is usually described in each instance as an incidental finding. Rarely, ectopic pancreas can cause intra-abdominal hemorrhage or obstruction. We studied a case in which aberrant pancreas located at the ampulla of Vater was found to be the cause of partial obstruction of the common bile duct. Resection of the duodenal papilla and anastomosis of the distal common duct to the duodenum resulted in complete cure. Treatment of the symptomatic patient with heterotopic pancreas demonstrated during gastrointestinal diagnostic examination, and the asymptomatic patient with ectopic pancreas discovered at laparotomy, are discussed.