In 17 patients (8 men, 9 women; mean age 61.5 years) with problematic bile-duct stones (papilla endoscopically inaccessible, residual bile-duct stones after recent laparoscopic cholecystectomy or age below 25 years) the chances of successful treatment by ESWL without sphincterotomy were examined. In 15 patients with solitary stones measuring up to 14 mm "pulverization-ESWL" produced complete freedom from stones after spontaneous migration of fragments through the intact papilla. Only two patients with two ductal stones measuring up to 15 mm still had residual fragments in the bile duct after treatment. The ideal stone for ESWL without sphincterotomy is thus the solitary bile-duct stone measuring up to 14 mm. Before performing a high-risk sphincterotomy, before re-operation and in young patients one should therefore always examine whether ESWL without sphincterotomy is indicated.