Percutaneous transhepatic cholangiography using a polyethylene catheter over a guide permitted successful diagnosis of obstructive jaundice in 95% of patients with calculi in the common duct, carcinoma of the head of the pancreas, papilla of Vater, common duct, or gallbladder, or recurrent neoplasms causing obstruction of the choledochojejunostomy following Whipple's procedure, indicating that this technique is a dependable means of establishing the etiologic diagnosis. Transduodenal cholangiography may be more helpful in the diagnosis of chronic pancreatitis. By creating a percutaneous biliary fistula to alleviate pruritus, some comfort may be afforded to patients with terminal disease.