Ultrasound examinations of 140 patients with a clinical suspicion of gallstones were compared with radiographic, surgical and pathologic findings to determine the accuracy of cholecystosonography. Ultrasound was 95% accurate for gallbladder disease, with a 5% false negative rate. Oral cholecystography was 96% accurate. The abnormal ultrasound examinations were divided into three groups, as described by Crade. Group 1 -- shadowing echoes within the gallbladder which move with gravity -- was 100% accurate for gallstones. Group 2 -- non-visualization of the gallbladder with acoustic shadowing -- was 94% accurate for gallstones. Group 3 -- non-shadowing echoes within the gallbladder -- was only 59% accurate for gallstones, but 96% accurate for gallbladder disease. We recommend cholecystosonography as the initial study in the investigation of gallbladder disease.