It is well known that realtime ultrasonography is the primary diagnostic modality to evaluate gallbaldder diseases. The authors studied ultrasonographic findings of 10 pathologically proven gallbladder carcinoma patients, and it was compared with the findings of 4 cases of ERCP and 2 cases CT which were performed at the same period. The results were as follows : 1. They were 6 males and 4 females with over 50 years of age except a 41 year old female. 2. The ultrasonographic classifications of the cases were 4 of fungating mass types, 3 of mass filling gallbladder types, 2 wall thickening rypes and 1 of mixed type, wall thickening and fungating mass. 3. Seven cases of cholecystitis, 6 cases of intrahepatic biliary duct dilatation, 5 cases of gallstone, 4 cases of common bile duct dilatation, 4 cases of sludge bile, 2 cases of gallbladder dilatation, 1 case of right subphrenic and pericholecystic abscess due to perforated gallbladder. 4. Five cases of mesenteric infiltration, 3 cases of hepatic infiltration adjacent to gallbladder, 2 cases of lymphatic metastasis to right lobe of liver and 2 cases of pericholedochal and pericaval lymph node metastasis. 5. The indistinct margin between gallbladder and surrounding organ adjacent to gallbladder mass or gallbladder wall thickening suggest cancer infiltration to adjacent organ such as liver or omentu. 6. If gallstone is engulfed in thickened gallbladder wall, the wall thickening suggests gallbladder carcinoma. 7. The differentiation between fungating mass and sludge bile, and the determination of mass could be done by positional change. 8. The preoperative ultrasonic diagnostic accuracy was in 9 out 10 cases (90%). 9. Because of the frequent cystic duct obstruction by associated inflammation, the diagnostic accuracy of ERCP for gallbladder carcinoma was low.