Percutaneous Tranthepatic Cholangiograhy (P.T.C.) is the most valuable diagnostic technique to differentate surgical jaundice from hepatocellular jaundice and to search the cause of the obstructive jaundice. P.T.C. using 23G Chiba needle has a high success rate in not only surgical jaundice cases but also medical problems of theliver and has a low risk. Authors present the clinical and P.T.C. findings of 189 cases which were experienced inlast 5 years, from July 1973 to August 1978, at the Dept. of Radiology, Seoul National University Hospital. The summerized results were as follows; 1. Among the 189 cases, male was 133 cases and female was 56 cases, and themale to female sex ratio was 2:1. 2. The most frequent P.T.C. diagnosis was common bile duct stoen (55 cases), and common bile duct cancer(54), pancreatic cancer (33), Cancer of Amppullar Vater (7), sclerosing cholangitis (5),clonorchiasis (4), gall bladder cancer (3), gall bladder stone (3), metastasis(3), hepatoma(3), C.B.D. stone,other (5), and normal (14), in decreasing order. The sum of three main disease, C.B.D. cancer and pancreatic cancer, was 75% of all cases. 3. The overall success rate of P.T.C. was 92.6%, and the diagnostic accuracy ofP.T.C. was 86.9%. 4. Confirmed 19 cases of misdaignosis was including 5 cases of gall bladder cancer, 4 of pancreatic cancer, 3 of common bile duct cancer, 2 of common bile duct stone, and others 5. All 4 cases of pancreatic cancer was misdiagnosed as common bile duct cancer. 5. Barium swallowing after P.T.C. was very usefulin differential diagnosis of obstructive jaundice giving information such as relative position of stomach, position of Ampulla Vater and the distance from Ampulla Vater to the obstruction site. 6. Major complication suchas hemoperitoneum, bile peritonitis, septicemia and sever hypotension was occurred in 6.5% of all P.T.C. cases.