Decrease in gall-bladder volume after intake of a test meal was assessed by ultrasound in 30 patients (24 females, 6 males; mean age 55 [22-82] years) with indications for elective or early elective cholecystectomy for cholelithiasis. Patients were assigned to three groups, based on intraoperative and histological gall-bladder changes: group 1 (n = 17), without changes or with mild chronic cholecystitis; group 2 (n = 4), with severe chronic inflammatory changes; group 3 (n = 9), with acute cholecystitis or cystic duct occlusion. A volume decrease of at least 30% after the test meal excluded only acute wall inflammation (negative predictive value 95.5%), while a volume reduction of at least 50% made it possible in a high percentage of cases (negative predictive value 88.2%) to predict correctly an absence of severe chronic wall changes. Before organ-preserving treatment (extracorporeal lithotripsy or local litholysis) is undertaken, gall-bladder volume reduction of at least 50% should be documented.