Reported are 10 patients with surgically verified acute cholecystitis and its complications. Of these 10 patients, 6 (60%) had atypical clinical presentation so that cholecystitis was not the primary diagnosis being considered before computed tomography. Common computed tomography findings included gallbladder wall thickening (100%), pericholecystic fluid (80%), gallstones (50%), and air in the gallbladder lumen and wall (20%). An awareness of the computed tomography appearances can be helpful in the diagnosis of complicated cholecystitis even when the clinical presentation is atypical.