Acute acalculous cholecystitis carries high morbidity and mortality rates, but if it is detected early, the prognosis for recovery is good. Detection requires diligence, because signs and symptoms may be nonspecific or atypical. Because their sensitivity and specificity are limited, the various imaging techniques available serve only as adjuncts to history taking and physical examination. Prompt initiation of treatment is essential to reduce complications. Options range from conservative medical therapy to aggressive surgical intervention. Recently, ultrasound-guided percutaneous cholecystostomy has become a favored approach. Best treatment varies, depending on underlying disease and the patient's condition.