The authors anlaysed retrospectively 56 cases of bile duct cancer, which were confirmed by histologically in 47 cases and highly suspected by clincially and radiologically in 9 cases. The results were as follows : 1. The most prevalent age groups were 5th and 6th decade and a male to female ratio is 2.7 : 1 . 2. The location of bile duct carcinomas were common bile duct in 36%, common hepatic duct in 25% junction in 13%, porta hepatis in 11% and diffuse invovement in 5%. 3. The accuracy of predicting obstruction site by ultrasonography was 76 %. 4. Correct diagnosis as bile duct carcinoma was made in 29 cases(43%). 5. The echogenicity of bile duct carcinoma compare to liver parenchyme was hyperechoic in 10 cases(34.5%). isoechoic in 14 cases(48,3%) , and hypoechoic in 5 cases(17.2%). 6. Posterior acoustic shadowing was seen in 5 cases. 7. The shape of obstruction site was abrupt cut-off in 12 cases(41%), funnel shape in 7 cases(24%) and indistinct in 10 cases(35%).