PTC is the single most valuable diagnostic method available to evaluate the size, shape and site of the causesof obstuctive jaundice among various radiological procedures. The authors reviewed and radiologically classifiedthe PTC films of 203 cases of obstructive jaundice from July 1977 to June 1983 at Presbyterian Medical Center,Jeon-ju confirmed clinically, operatively and pathologically. The resuls are as follows; 1. The most common causeof obstructive jaundice was bile duct stoen (64/203:31.53%) and the other causes were bile duct cancer(43/203:21.18%), pancreas cancer(41/203:20.19%), biliary ascariasis &/or clonorchiasis(20/203:9.85%), ampulla andduodenal cancer (7/203:3.45%), fibrotic stenosis of sphincter of Oddi(6/203: 2.96%) etc. in that order. Of theseprimary involvement with cancer was more frequent (91/203:44.33%) than stone. 2. 88.33%(179/203) of patients wasover 40-year-of- age and the sex ratio between male and female was about 2:1. 3. The average maximal diameter ofextrahepatic bile duct just proximal to the site of obstruction or stenosis by stones or by cancers was nearlyequal(2.36cm:2.38cm). 4. Cancers caused complete bile duct obstruction in about 75%(68/91) of cases and also wereassociated with intrahepatic duct dilatation about 92%(84/91) of cases. But in contrast biliary calculi showedgood drainage of contrast medium in 75%(48/64) of cases and 92%(59/64) showed normal diameter of intrahepaticduct. 5. The differential PTC findings between bile duct cancer and pancreas cancer were not so distinct but inbiel duct cancer the obstruction site of the bile duct was more irregular and serrated than pancreas cancer, whilethe latter showed a more downward convexity and a smoother end. Moreover annular filling defect with overhangingedges was seen only in bile duct cancer.