Anomalous pancreaticobiliary union (APBU) has varied presentations. We report the case of a 12-year-old female who presented with biliary peritonitis due to a perforation of the common bile duct due to impaction of a pancreatic calculus at the duodenal␣ papilla. She had a long common-biliary channel and pancreas divisum with chronic calcific pancreatitis involving the pancreatic head and neck. To our knowledge, this is the first such reported case in the literature.