Percutaneous transhepatic cholangiography (P.T.C) is a most valuable procedure in differentiation ofobstructive jaundice, wheter benign (chiefly stone) or malignant condition. Authers present the clinical and P.T.C. findings of 30 cases of obstructive jaundice which were experienced from Dec. 1975 to May 1977, at department ofRadiology, Kyung-pook National University Hospital. The summerized results were as follows. 1. The incidence ofmalignancy beyond the age of 40 was high compared with stone, which revealed relatively equal age distribution. 2.The stone showed as concave cupping in all case (11 cases), but the malignancy showed as nipple formation (10 cases) and irregular narrowings (9 cases). 3. The dilation of the intrahepatic bile duct appeared 10 cases onmalignancy among 19 cases of malignancy (52.6%) and 4 cases on stone which were multiple intrahepatic or commonhepatic duct stones. 4. The dilation of the just proximal bile duct was severe on malignancy compared with stone.5. The mean bilirubin level was high on malignancy (12.8mg-%) compared with stone (10.3mg-%).