Endoscopic sphincterotomy was performed in 469 patients for the treatment of biliary calculi, with procedure-related morbidity of 6.3% and mortality of 0.4%. Long-term follow-up to 10.5 years (mean 3.7 years) was completed in all of 408 patients at least six months postsphincterotomy. Recurrent stones developed in 21 patients (5.8%) after a mean of 2.4 years (range 4 months to 7 years); in 6 after 3 years. Eight patients reformed stones more than twice at a mean interval of 1.8 years (range, 5 months to 3.5 years). In the 122 patients with gallbladders in situ, acute cholecystitis occurred in 5 of 31 with gallstones (16%), but in none of the 91 without gallstones. In the 237 patients who had undergone cholecystectomy, 4 late deaths occurred secondary to recurrent choledocholithiasis and cholangitis. In the 49 patients with primary intrahepatic stones, 3 late deaths occurred secondary to hepatic abscess. These results suggest that (a) endoscopic sphincterotomy is a very effective procedure in long-term follow-up, (b) cholangiography should be done at the appearance of slight abdominal symptoms even after 3 years, (c) patients who have ever reformed stones should undergo cholangiography yearly for at least 4 years, and (d) cholecystectomy is recommended for patients with gallbladders after sphincterotomy, only if gallstones are present.