A 69-year-old woman had a history of acute pancreatitis. On abdominal computed tomography, the pancreatic body and tail could not be visualized, and the pancreatic head encircled the descending part of the duodenum. On endoscopic retrograde cholangiopancreatography, we could not find the minor papilla. The major papilla was located on the lateral wall of the descending part of the duodenum. The pancreatic duct was short, and the common bile duct was on the lateral side of the duodenum near the hepatic hilum. We diagnosed polysplenia syndrome with annular pancreas and agenesis of the dorsal pancreas. The syndrome includes several congenital anomalies, but there is very little information currently available about this particular syndrome. We report our patient's case and review the pertinent literature.