TTHERE ARE FEW problems more perplexing than the differential diagnosis of the jaundiced patient. Oral and intravenous cholangiography are not applicable in the presence of jaundice, and if jaundice has been present for any prolonged period, the usual chemical tests are of limited value in differentiating extrahepatic obstructive from hepatocellular jaundice. Percutaneous transhepatic cholangiography, however, will reveal the pathologic anatomy of the biliary tree in the presence of jaundice. In some cases it can distinguish obstructive from hepatocellular jaundice, and obviate laparotomy on a patient with hepatitis. In those patients with extrahepatic obstruction, the precise pathologic anatomy of the biliary tree is demonstrated preoperatively, and thus may save valuable operative time. The indications for percutaneous cholangiography are:: I. (A) To investigate jaundice of obscure etiology; this may differentiate hepatocellular from extrahepatic obstructive jaundice and/or; (B) Locate the level of extrahepatic obstruction, and distinguish carcinoma of the head of the pancreas