Our purpose was to analyse the results of endoscopic sphincterotomy in patients with advanced cholangitis, and to assess the potential of this method in the prevention of recurrent biliary tract stones. Advanced cholangitis certainly predisposes to microlith formation, and we believe that the increased biliary drainage produced by sphincterotomy counteracts this process. Our grading of cholangitis was an intraoperative cholangioscopic assessment corresponding to Nishimura grades III and IV (erosions in the duct walls, patchy stone ulceration, biliary gravel, fibro-purulent plaques densely adherent to the biliary walls etc. 62 patients with grades III and IV cholangitis (as defined at choledochoscopy) underwent endoscopic sphincterotomy (GP-A). This group underwent a controlled prospective study with review at: one year, between 2 and 3 years, 5 years following surgery. The control group (GP-B) constituted 20 patients with comparable cholangitis who did not undergo sphincterotomy. Group A had no recurrent lithiasis, 4.8% revealed persistent cholangitis. In control group (GP-B) 6 patients (30%) revealed recurrent lithiasis, on average 4.6 years following initial surgery. In addition, 35% of this group had clinical symptoms of cholangitis. These results indicate that endoscopic sphincterotomy is a worthwhile method in the treatment of cholangitis and prophylaxis against recurrent biliary tract stones.