1. 1. The anatomy and physiology of the constricting mechanisms at the lower end of the common duct are reviewed. 2. 2. The need for complete elimination of these operations are demonstrable by postcertain cases of recurrent pancreatitis and in problems of extrahepatic biliary obstruction has been stressed. 3. 3. Elimination of these sphincteric mechanisms requires sphincteroplasty and cannot be accomplished by sphincterotomy. 4. 4. Key points in the technic of sphincteroplasty are outlined. 5. 5. The importance of a pancreatic ductogram in selecting the surgical approach in patients with recurrent pancreatitis is re-emphasized. 6. 6. The anatomic differences between sphincteroplasty and sphincterotomy are described. 7. 7. The physiologic differences between these operations are demonstrable by postoperative T tube pressure studies, postoperative T tube cholangiograms, postoperative cineradiography, postoperative upper gastrointestinal studies, and clinical results. 8. 8. Indications and contraindications for sphincteroplasty are outlined. 9. 9. Two hundred forty-one sphincteroplasties are reported with an over-all mortality of 1.24 per cent and a morbidity of 4.9 per cent. 10. 10. Of the ninety-five patients with recurrent pancreatitis and no intrapancreatic ductal obstruction, 90.5 per cent were improved or asymptomatic after sphincteroplasty. This optimistic figure is misleading since forty-four of the ninety-five patients had calculous biliary tract disease, and a substantial number might have been relieved by eradication of this alone. However, in fifty patients with recurrent pancreatitis, no calculous disease, and no intrapancreatic ductal obstruction, the benefits derived appear to be due to the sphincteroplasty. 11. 11. All of the 146 patients with extrahepatic biliary tract obstruction were relieved of symptoms by sphincteroplasty. One hundred thirty-nine of these were operated upon for multiple common duct stones. No recurrent or residual stones developed after sphincteroplasty. 12. 12. Although sphincteroplasty should be performed only by a surgeon familiar with biliary tract surgery, we believe that if the technic outlined is carefully followed, the operation may be accomplished with minimal morbidity and mortality.