Aim. Determination of the effectiveness of the improved method of sphincterotomy in choledocholithiasis, called radial sphincterotomy. Methods. Analyzed were results of 38 operations performed by endoscopic retrograde cholangiopancreatography in patients with a diagnosis of choledocholithiasis. In the first group (23 patients) performed a standard sphincterotomy, in the second group - radial sphincterotomy. 21 patients of the first group had gallstones up to 20 mm, 2 patients - more than 20 mm; in 6 patients (out of 15) of a second group gallstones sizes exceeded 20 mm, the other patients had stones sizes 15-20 mm. Results. The technique developed radial sphincterotomy allows multiple incisions towards 11, 12 and 13 hour clock directions. Thus, the main incision can be made to the transverse folds, and other radial incisions should be carried out below it, not going beyond the proposed location of the intramural common bile duct. Anatomical and mathematical justifications of the method of radial sphincterotomy were presented. Depending on the cut and shape of papillae, the severity of the upper transverse folds defining a safe distance from the hole until it papillae, performed lateral radial incisions, thereby achieving an increase of sphincterotomy cut altogether. Neither group registered death. In 2 (8.7%) patients of the first group bleeding occurred during the procedure, after the operation pancreatitis has developed in 1 (4.3%) patients in first group and in 1 (6.7%) patients in the second group. Conclusion. The proposed technique of radial sphincterotomy is a safe way to increase the area of dissected papillae to provide high efficiency for removal of large gallstones.