Purpose : To evaluate the usefulness in diagnosing the gallbladder perforationMaterials and Methods : CT scans of surgically proved 11 cases of gallbladder perforation were retrospectively reviewed. CT findings analyzed were luminal diameter of GB, GB wall thickness and configuration, presence or absence of fluid collection in the pericholecystic or intraperitoneal space, and observation of pericholecystic anatomic structures. All patients under went cholecystectomy, and surgical findings were also compared. Results : The GB was distended in 6 cases(55%with a range of 4.0-7.5cm, mean:5.2cm). GB wall was thickened in most cases(9/11, 82%) with homogeneous(n=7) orinhomogeneous(n=2) enhancement. At the sites of perforation, focal defect or contour bulging was seen in the GBwall in 3 cases. In 2 cases with gangrene, GB wall showed loss of normal contour with mottled contrast enhancement. Pericholecystic or intraperitoneal fluid collection was noted in 9 cases(82%), especially in the region of perforation. In all cases, there was evidence of diffuse infiltration in the pericholecystic space, omentum or mesentery. Other findings included cholecystoenteric fistula in 1 case, and intrahepatic or intraperitoneal abscess formation in 2 cases. Conclusion : CT is useful in correct diagnosis of gallbladder perforation.