Eighty three patients with suspicious biliary obstruction were investigated with ultrasonography and other diagnostic methods to evaluate diagnostic accuracy of ultrasonography in obsrtuctive jaundice. Correct recognition of the biliary tree was accomplished by ultrasonography in 85% of cases with dilated biliary tree and 90% of cases without dilated biliary tree. The sensitivity' of ultrasonography in diagnosis of bile duct stone and malignancy was 66% and 63%, respectively. The positive predictability of ultrasonography of bile duct stone and malignancy was 72% and 100%, respectively. The role of ultrasonography including advantage, disadvantage and limitation in evaluating obstructive jaundice is discussed.