Primary endoscopic removal of bile duct stones is an established method of treatment. However, the extraction of stones is impossible in about 10% of cases despite successful endoscopic papillotomy and manual lithotripsy. Over a period of two years extracorporeal shock-wave lithotripsy (ESWL) was performed in 32 patients. Piezolith 2200, a second generation lithotripter was used, which requires neither analgesia nor anaesthesia for the patient. Localisation of the stones was carried out by means of a 3.5 MH 2 sector scanner. ESWL treatment was successful in 24 of 32 patients (75%). In 6 patients the bile duct stones were too large or too numerous and in 2 patients sonographic localisation was impossible. Out of a total of 131 patients with stones in the biliary tract only 9 (6.8%) needed surgery. Piezoelectric lithotripsy is a safe and effective adjunct procedure for the treatment of bile duct stones which were not extractable by endoscopy.