We report the case of a 19-year-old woman with abdominal pain and diarrhea. The diagnosis of acute pancreatitis could be made clinically and through laboratory tests. The cause was a duodenal duplication cyst in the area of the papilla, which was initially relieved endoscopically. Once the acute inflammation had healed, the cyst was resected endoscopically to prevent recurrence and the increased risk of malignancy. Duodenal duplication cysts in the papillary area are a very rare (congenital) cause of acute pancreatitis. If a cyst is present in the area of the duodenal wall, however, this differential diagnosis should be considered. Resection is indicated for therapy.