The Authors report their experience in 38 cases (January 1990-Septembre 1994) of "difficult" gallstone disease of the main bile duct treated with electrohydraulic intracorporeal lithotripsy. Nineteen patients were affected with giant stones of the biliary tree, 6 with multiple stones of the main bile duct, 13 with stones of one or both hepatic ducts. The approach to the biliary tree was peroral transpapillary in 16 patients and transhepatic in the remaining 22. Twenty-five patients were previously submitted to surgery of the biliary tree (13 hepaticojejunostomy, 8 choledochoduodenostony, 4 papillostomy), while 5 had required a cholecystectomy, and 6 a gastroresection according to Billroth II. In 80% of the cases two lithotripsy sessions were enough to achieve the complete clearing of the bile duct. There was no mortality and morbidity was 5.3%. Total clearing was obtained in 97.4% of the cases. 6-48 months after treatment 37 patients still do not show clinical, laboratory or echographic signs of gallstone stasis or disease relapse.