After medical sphincter dilation using sud-lingual nitroglycerin, endoscopic removal of common bile duct stones in 15 patients was carried out. Complete stone removal was obtained in 14 of 15 patients. Only 0.3 mg to 0.6 mg nitroglycerin was needed to give an enough dilation of the orifice for cannulating the basket catheter into the bile duct. Mechanical lithotriptor was smoothly cannulated in one patient because of possible impaction. Blood pressure was dropped transiently in one patient by nitroglycerin, however, the general condition of the patient was stable. This procedure is safe, easy and effective in preserving sphincter function. Acute cholecystitis, a common complication of persistent gallbladder stone after endoscopic sphincterotomy, may be avoided by employing this method. More clinical studies, on long term and in a large scale of patients, are necessary to reduce complications that usually occur after sphincterotomy.