Over a period of one year, 75 patients with jaundice were evaluated by grey scale ultrasonography. Intravenous cholangiography was attempted in 26 instances (bilirubin value greater than 4.3 mg/100 ml) and was diagnostic in only four. Ultrasound, on the other hand, was diagnostic for surgical jaundice in 62 of the 75 cases (82%). In 52 of the 62 patients a cause for the extrahepatic obstruction was demonstrated: 40 had cholelithiasis and choledocholithiasis, and 12 had tumors (11 pancreatic tumors, one lymphoma). In the remaining ten instances, obstruction was sonographically demonstrated but the cause was not. Of these, four patients were subsequently proven to have distal common duct stones, five had carcinoma of the pancreas and one had cholangiocarcinoma. This evidence indicates that ultrasound should be the noninvasive procedure of choice in the clinical assessment of obstructive jaundice.