A retrospective review of the records of 1,507 patients with a diagnosis of cholecystitis was conducted for the five-year period, 1972 to 1977. Of this group of patients, a histopathologic diagnosis of acute cholecystitis was established in 154 patients (10.2%). Common duct calculi were detected in 17 of these 154 patients, an incidence of 11%. Preoperative evaluation by means of serum bilirubin and alkaline phosphatase levels and intravenous cholangiography was unsatisfactory for consistent demonstration of choledocholithiasis in the presence of acute cholecystitis. Intraoperative cholangiography was found to be the most reliable method for detection of common duct calculi and was successfully employed in 14 of 17 patients with choledocholithiasis. The remaining three patients had palpable stones.