We treated nine patients with functioning gallbladders containing one to three symptomatic radiolucent stones not larger than 25 mm in diameter, as well as five patients with stones in the common bile duct that were not removable by endoscopic procedures, by means of extracorporeally generated shock waves during general anesthesia. The patients with gallbladder stones received adjuvant treatment with a combination of ursodeoxycholic acid and chenodeoxycholic acid. All gallbladder stones were disintegrated into sludge or fragments with diameters of no more than 8 mm. In six of the nine patients the fragments disappeared completely within 1 to 25 weeks. No adverse effects were detected during a follow-up period of 10 to 34 weeks, except transient biliary pain in two patients, with mild pancreatitis in one. In four of the five patients with common-bile-duct stones, shock-wave treatment permitted stone disintegration and successful endoscopic extraction or spontaneous passage of fragments. We conclude that gallstone disease may be treated successfully and without serious adverse effects by extracorporeally generated shock waves in selected patients.