We used a pulsed tunable dye laser (operating at 60 mJ per pulse, 504-nm wavelength) to fragment large (0.8-4.5 cm) stones retained in the hepatic ducts or common bile duct in 12 patients after cholecystectomy. Attempts to extract stones via a T-tube or endoscope had been unsuccessful in all patients. In nine of 12 patients, all stone fragments were successfully eliminated during the initial treatment. In one patient, fragmentation occurred but debris remained, requiring endoscopic stenting. Pseudomonas sepsis developed in this patient 30 days after the procedure and was treated by extraction of the stone fragments. Fragments remaining after lithotripsy were cleared at the same sitting by using saline flushing or endoscopic or percutaneous basket extraction. In two of 12 patients, the treatment was unsuccessful because of laser malfunction. The treatment was performed without complications, except for clinically insignificant hyperamylasemia, which occurred in two patients. Our experience suggests that laser lithotripsy offers a safe alternative for nonsurgical treatment of large retained biliary stones for patients in whom traditional treatments have failed.