Here we report a patient with a pancreaticobiliary fistula that was possibly associated with pancreatolithiasis. He was admitted due to mild pancreatitis. Pancreatolithiasis was revealed in the parenchyma of the head region and in the main pancreatic duct of the pancreas body with distal dilatation. Extracorporeal shock wave lithotripsy (ESWL) effectively eliminated the pancreatic stones; however, an apparent internal fistula from the middle portion of the common bile duct (CBD) to the main pancreatic duct was revealed where the parenchymal stones had been located. The patient was considered to be in the same condition as pancreato-biliary malunion without CBD dilatation, and was treated with laparoscopic cholecystectomy.