Findings from studies showing an increased incidence of gallstones in diabetic patients do not control for other variables, such as obesity. There is no proof that diabetic patients have more gallstones. Gallstones do not cause diabetes mellitus. The principal gallbladder pathologic feature in diabetic patients is a functional deficit of uncertain etiologic factors, creating a large, flaccid, poorly emptying organ. Bile acid and lipid composition are usually increased in diabetic patients. Cholecystitis seems to be a more serious disease in diabetic patients, with worse infectious sequelae and more rapid disease progression. This conclusion has not been examined statistically. Even with modern care, the complication rate for operations upon the biliary tract in patients with diabetes is increased. Those with diabetes are generally older than other patients requiring cholecystectomy. Systemic changes of aging partly explain increased morbidity and mortality. Diabetic patients with symptomatic gallbladder disease usually require operation. Risk of cholecystectomy in diabetic patients is similar to that in nondiabetics. Prophylactic cholecystectomy for diabetic patients with "silent" gallstones was formerly recommended because of an apparent high risk of cholecystitis. Until the natural history of gallstones in those with diabetes has been defined, such patients should be considered in danger of serious illness. The risk of acute cholecystitis in diabetic patients with stones is probably significant enough to warrant the performance of early cholecystectomy.