We treated twenty-three patients with common bile duct stones (12 female, 11 male, mean age: 67.1 years) by Extracorporeal Shock Wave Lithotripsy (ESWL). The stones were focused by ultrasonic or choledochographic localization. The twenty-three patients received 53 ESWL treatments consisting of mean 2357 shocks per treatment at mean 18 kV. We performed ESWL in five cases with endoscopically unextractable common bile duct stones after endoscopic sphincterotomy (EST). In these cases, ESWL permitted stone disintegration and successful endoscopic extraction of the fragments. We performed ESWL in eighteen cases with common bile duct stones without EST. In fifteen of the eighteen cases (83%), fragmentation was achieved. The stone fragments were spontaneously discharged in ten cases (56%) after a median of 4 days following ESWL. In five cases, adjutant endoscopic procedures were performed. The complete fragmentation and the clearance rate for stones of diameter of less than 10 mm were higher than that for stones of diameter of more than 11 mm. In the cases with the stones of diameter of more than 10 mm, there is a very strong possibility that complete clearance is achieved by ESWL alone. No correlation was obtained for the effective results according to pretreatment number of stones. In eight of thirteen cases (62%) with gall bladder stones, complete clearance was achieved without EST. ESWL without EST can be thought as a rational treatment for preserving the function of papilla of Vater in the case of cholecysto-choledocholithiasis.