512 patients with gallbladder stones (393 females, mean age 52.7 years; 119 males, mean age 46.9 years) were treated by extracorporeal shock wave lithotripsy with an electrohydraulic Dornier MPL 9000 lithotripter. The Munich criteria were used for patients selection. Midazolam (15 mg im) and piritramid (mean 7.5 mg iv) were administered as analgetics. Stone fragmentation was achieved after an average of 1.92 treatment sessions. In 12 cases (2.3%) there was no fragmentation. Ursodeoxycholic acid (10 mg/kg/day) was administered as adjuvant litholytic therapy until 3 months after total fragment clearance. During a period of a year the patients returned for follow-up investigations in decreasing number. The total fragment clearance rate was 43.3%, for the I. group (single stone of 5 to 20 mm) was 58%, for the II. group (single stone of 21 to 30 mm) was 28.6%, for the III. group (2 or 3 stones of 30 mm maximum diameter) was 21.4%. In 12 cases (1.2%) vasovagal reactions, in 31 cases (3.1%) atrial and ventricular extrasystoles, in 27 cases (2.7%) transient gross hematuria were observed. During a period of a year 18 cholecystitis (3.5%), 8 pancreatitis (1.56%) and 5 obstructive jaundice (0.97%) developed. 28 cholecystectomies (5.4%), 1 necrectomy because of necrotic pancreatitis (0.19%) and 5 endoscopic sphincterotomies (0.97%) were required.