Gastroduodenal duplication is a rare congenital entity. Preoperative diagnosis is difficult because symptoms are usually non specific and can mimick pancreatitis. We report 2 cases of gastric and duodenal cystic duplication in adults presenting as pancreatitis. Chronic pancreatitis was observed on endoscopic retrograde pancreatography and confirmed at laparotomy in both cases. Pancreatitis was probably related to alcoholism in one case, but might have been secondary to duplication in the other. In both cases, duplication was misinterpreted initially as a pseudocystic complication of pancreatitis until laparotomy was performed. These 2 cases lead us to discuss the relationship between duplication and pancreatitis.