Since its introduction in 1924, oral cholecystography has been used as a screening method in the diagnosis ofthe gallbladder disease. Recently, intravenous cholangiography has become a most valuable method in the diagnosisof biliary tract pathology beause of its advantage of simultaneous visualization of the gallbladder and bile ductsin a short time. However, opinions vary considerably as to the significance of nonvisualization of the gallbladderwith oral cholecystography. In attempt to evaluate how much intravenous cholangiography does contribute to thediagnosis in the cases that the gallbladder connot be opacified or can only faintly visualized by the oral method,we have made a clinical observation in 168 patients, in whom intravenous cholangiography had been performed withina week following oral cholecystography, at Korea General Hospital during the last three years from Jan. 1969 toDec. 1971. The results obtained are summarized as follows; 1. The results of oral cholecystography in 168 caseswere as follow; well opacification of the gallbladder in 10 cases, faint opacification in 46 cases andnonopacification in 112 cases. 2. In 37.5%(42 cases) of 112 gallbladder not opacified by the oral method, thegallbladder was subsquently opacified by the intravenous method, and 11.6%(14 cases) turned out to be normal whenexamined by the intravenous method. 3. Further demonstration of abnomralities could be obtained with the aid ofintravenous cholangiography in 28 cases(16.6%); cholelithiasis in 12 cases and choledocholithiasis in 16 cases. 4.In every cases of 14 patients whose gallbladder were virtually not opacified by both oral and intravenous methodsbut the common bile ducts could be opacified by intravenous cholangiography, definite abnormallites wereidentified in the gallbaldder at surgery.