One hundred and fifty patients with jaundice and analytical suspicion of extrahepatic cholestasis were studied prospectively; history laboratory investigation and ultrasound examination were done in all. Computerized tomography was performed in 46 patients. Ultrasonography has a sensitivity of 92.6% while that of computerized tomography was 87.2% for the identification of dilated biliary ducts. Computerized tomography demonstrated the level of obstruction with a sensitivity of 89.1%, being most useful at the suprapancreatic and ampullary levels, while ultrasound examination had a sensitivity of 80%. The accuracy of ultrasonography was higher than the one obtained in computerized tomography in cholangiocarcinoma (sensitivity: 77%) and gallbladder carcinoma (sensitivity: 100%). Computerized tomography recognized choledocholithiasis (sensitivity: 83%) and ampullary carcinoma (sensitivity: 75%) with better accuracy. However for pancreatic carcinoma (sensitivity: 87%) and pancreatitis (sensitivity: 88%) both examinations had the same accuracy.