Heterotopic pancreatic tissue of the stomach is a rare condition. Gastric diverticulum is also a rare condition, mostly located at the fornix. Therefore, the existence of a pyloric gastric diverticulum containing a submucosal tumor proved to be heterotopic pancreatic tissue of the stomach is an extremely rare condition. The patient was a young thin male with epigastralgia chronically treated for gastritis/ulcer. Following an episode of melena, he underwent gastroscopy that diagnosed antral gastric diverticulum containing a polyp. The lesion was surgically removed. The pathology report stated: heterotopic pancreatic tissue of the stomach with secondary development of a traction diverticulum. Heterotopic pancreas tissue of the stomach is a rare condition but the association with gastric diverticulum is completely unusual. The possibility of the ectopic tissue leading to secondary diverticulum development should be considered.