A new endoscopic method for treatment of choledocholithiasis in patients with choledochoduodenal fistula is described. In 2 patients with common bile duct stones a choledochoduodenostomy was performed by means of a diathermy snare. In both patients the calculi passed into the duodenum within some days. No complications occurred. It is concluded that the described technique may be helpful when surgery is contraindicated and when endoscopic papillotomy is difficult to perform.