Acute pancreatitis may occur after the performance of endoscopic retrograde cholangiopancreatography (ERCP) and endoscopic sphincterotomy. During ERCP and endoscopic sphincterotomy, the pancreas is subjected to many types of potential injury--mechanical, chemical, hydrostatic, enzymatic, microbiological, allergic, and thermal. These factors may act independently or in concert to induce postprocedure pancreatitis. The potential role of each etiologic factor in the development of ERCP- and endoscopic sphincterotomy-induced pancreatitis is detailed. The management of this complication is reviewed. Patient factors that increase the risk for pancreatitis and techniques to prevent or limit this complication are described. A variety of agents have been shown to prevent or treat pancreatitis in animal models, but extrapolation to humans has been almost uniformly unsuccessful. Although postprocedure pancreatitis is unlikely to be completely eliminated, careful patient selection and attention to detail may reduce the incidence of this untoward event.