Endoscopic sphincterotomy has allowed us to extract relatively large stones from the common bile duct as compared with other methods utilizing a T-tube tract or the percutaneous transhepatic route. Twenty-four patients with large stones over 20 mm in diameter were selected and reviewed from a series of 469 sphincterotomy patients. Eleven stones passed into the duodenum spontaneously, the maximal size of which was 30 by 43 mm. Passage occurred within 4 days after sphincterotomy in 27 percent, 5 to 7 days after the procedure in 55 percent, and 8 to 13 days after the procedure in 18 percent and was accompanied by cholangitis in 55 percent of the patients. The small diameter of the stone and common bile duct dilatation down to the distal end seemed to be the factors favoring stone delivery. Five stones were removed using ordinary basket catheters by duodenoscopy; however, the largest one required 28 attempts. More recently, four stones were efficiently extracted after destruction by electrohydraulic or mechanical lithotripsy. Failure of removal in five patients was mainly due to a lack of space around the stone for basket manipulation or occurrence of severe cholangitis. Further refinements in technique in this regard are needed.