Acute acalculous cholecystitis occurs infrequently, but the incidence seems to be increasing. Its attendant high associated morbidity and mortality dictate prompt diagnosis. Diagnosing this condition is often difficult because of the patient's debilitated medical condition and the limitations of biliary imaging techniques. During a 5-year study period (1981 through 1986), 20 patients underwent assessment and treatment for acute acalculous cholecystitis at our institution. This observation suggests an increase in incidence in comparison with a previously reported review of 28 such patients during a 16-year period at our institution. Initial treatment consisted of cholecystectomy in 18 patients, and percutaneous transhepatic cholecystostomy was successfully used in the other 2 patients. The postoperative mortality and morbidity for these 20 patients were 30% and 55%, respectively. Percutaneous transhepatic cholecystostomy should be explored further as a treatment option for acute acalculous cholecystitis.