Abstract The presence of various degrees of hypoplasia of the biliary system presents particular difficulty in diagnosis and differentiation from biliary atresia. Two cases are presented in which there was a reduction in serum bilirubin after laparotomy with a diagnosis of biliary atresia. One of these patients appears normal two years later. Reexploration and cholangiography revealed a hypoplastic ductal system in both of the patients. Recognition of this entity will be aided by careful cholangiography and dissection. Failure to visualize the biliary ductal system need not presume a fatal diagnosis.