The patient who presents with jaundice, regardless of the etiology, cannot be adequately examined by a gallbladder series and intravenous cholangiography. Clinical evaluation aided by laboratory analysis will not always differentiate between primary liver parenchymal disease and biliary tract obstruction. Percutaneous transhepatic cholangiography, when successfully performed, answers the question of whether the jaundice is due to primary liver parenchymal disease or due to biliary tract obstruction. The point to emphasize is that under no circumstances is it appropriate to presume any information if the biliary system is not entered and visualized successfully. The proper interpretation of the level of block can fall prey to the mistake of incomplete aspiration of the thick, inspissated bile in the obstructed biliary tree before injection of contrast material. The problem will be worsened by a peripheral entrance into the biliary system rather than a more central one. Gastrointestinal series should always be available to aid in identifying pathology at the entrace of the common bile duct into the duodenum. Lastly, identifying the etiology at the site of the block will require additional procedures. Selective visceral angiography has contributed greatly in this area. During the 20 years of clinical usage of percutaneous transhepatic cholangiography, we feel it has become the single examination capable of preventing unnecessary exploration of the jaundiced patient with primary liver parenchymal disease and the most useful potential source of practical information if laparotomy is necessary to correct biliary tract obstruction.