Perforation is a rare but serious complication of a duodenal diverticulum and often presents itself with nonspecific symptoms and signs. Ectopic pancreatic tissue within a duodenal diverticulum is another rare situation. In this article, we report a case of an 87 year-old woman who presented with spontaneous perforation of the duodenal diverticulum. Operative resection and simple closure of the duodenum was performed. Ectopic pancreatic tissue was observed within the diverticulum at histological evaluation.