Pancreaticobiliary maljunction (PBM) is a congenital malformation in which the pancreatic and bile ducts join anatomically outside the duodenal wall. Since the duodenal papillary sphincter fails to exert any influence on the pancreaticobiliary junction, reciprocal reflux between pancreatic juice and bile occurs, resulting in various pathologic conditions in the biliary tract and pancreas. For diagnosis of PBM, an abnormally long common channel and/or an abnormal union between the pancreatic and bile ducts must be evident on direct cholangiography, such as endoscopic retrograde cholangiopancreatography, percutaneous transpehatic cholangiography, or intraoperative cholangiography; magnetic resonance cholangiopancreatography; or three-dimensional drip infusion cholangiography computed tomography. Elevated amylase levels in bile and extrahepatic bile duct dilatation strongly suggest the existence of PBM.