Selective access into the desired duct followed by incision of the sphincter, i. e. sphincterotomy, forms the cornerstone of any endoscopic intervention within the pancreaticobiliary system. The apprehensive beginner's performance and hesitance is aggravated by ignorance of ampullary anatomy and he considers selective cannulation to be the greatest hurdle. An understanding of ampullary morphology and its variations is vital in achieving selective cannulation. Technological advances have assisted in the form of development of better accessories, progressing from "immovable" catheters to movable cannulae and to single-, double-, and even triple-lumen sphincterotomes. Orientation along the long axis of the bile duct ensures access and avoids inadvertent and hazardous manipulation of the pancreatitic duct. Using guide wires, especially the 'angulated-tip' glide wire improves cannulation successs rates considerably. Precut accessotomy complements wire-guided selective cannulation, and can be used analogously to a controlled surgical incision to facilitate cannulation of the desired system after deroofing the papilla layer by layer. Published data have validated its role, demonstrating high efficacy and minimal complications when it is properly performed. Biliary sphincterotomy, using the right mode of blended current in the 11-12 o'clock direction and with the tip of the sphincterotome wire, provides a clean and bloodless splitting open of the sphincter of Oddi. Pancreatic precut, over-the-stent papillotomy and sphincterotomy over a guide wire have all been proven to be safe and effective measures, in large groups of patients. In special situations, such as where there are impacted stones or ampullary lesions, needle-knife infundibulotomy achieves reliable access. Techniques such as saline infiltration into the papilla and subtle body movements to re-position the scope enable biliary cannulation in difficult situations. Alterations in anatomy, for instance post Billroth II gastrectomy, no longer discourage the endoscopist from attempting intervention. Application of knowledge of reverse anatomy, specially designed instruments, and adherence to the proper technique improves success in these patients. Our experience of 9000 sphincterotomies over the past 12 years with minimal morbidity stands proof to the principles and techniques highlighted in this monograph. We recommend these to all aspiring endoscopists, with the assurance of improved technical success when they are implemented.