The purpose of this paper is to describe the bile duct and the pancreatic duct anomalies associated with congenital upper intestinal obstruction based on the findings of the upper gastrointestinal series and the cholangiography. There were 3 cases with the reflux of the contrast media to the bile duct or the pancreatic duct on the upper gastrointestinal series. One case with the reflux to the bile duct had congenital duodenal membranous stenosis, and 2 cases to the pancreatic duct had annular pancreas. There were 4 cases with anomalies of the bile duct (2 cases with ectopic opening of ampulla, 1 case with choledocal dilatation and 1 case with abnormal cystic duct). We suppose that the reflux to the bile duct (duodeno-choledocho reflux) and to the pancreatic duct (duodeno-pancreatico reflux) may occur by duodenal dilatation and sphincter-anomaly of the choledocus and pancreatic duct, and these cases with the reflux may be associated with cholangitis or pancreatitis,
