The value of ultrasonography and percutaneous transhepatic cholangiography in determining the site andetiology of biliary obstruction with surgical jaundice was studied in 30 patients. All diagnoses were subsequentlymade by surgery and pathology. The results were as follows; 1. In ultrasonography, the site of obstruction wasdelineated in 46%, while the etiology of the lesion was established in 40%, In comparison, percutaneoustranshepatic cholangiography delineated the site in 100% and the etilogy in 93%. 2. Although the percutaneoustranshepatic cholangiography is invasive to the human body, it is considered to be the single procedure of choicein the managment of the patient with biliary obstructive jaundice because of its diagnostic accuracy, technicalsimplicity and relative safety.