Treatment of the pathology of the extrahepatic biliary tract is the most frequent indication for performing endoscopic retrograde cholangiography (ERCP). The method, which combines endoscopic and radiological vision, also allows for therapeutic (and diagnostic) procedures on some pathologies of the pancreas and the papilla of Vater. During the maneuvers it is also possible to obtain cyto-histological material for the diagnosis of any lesions identified, through the execution of brushing. The endoscope used for ERCP allows for microsurgical procedures to be performed on the papilla of Vater, on the biliary tract and on the pancreas, procedures that in the past required a real surgical intervention. ERCP is a generally well tolerated procedure, but as with all medical procedures it can have limitations and be followed by some complications. In 5% of cases, the procedure may not be completed due to anatomical variants that do not allow the endoscope to reach the duodenum or to cannulate and visualize the bile and / or pancreatic ducts. The most frequent complication is acute pancreatitis, which can arise as a consequence of surgery on the common outlet of the biliary and pancreatic tracts; it occurs in 3-5% of cases and to date, it cannot be predicted or prevented in all cases. In some groups of patients (young, with non-dilated biliary tract, or with a history of previous pancreatitis) the risk of pancreatitis can reach 10-12% . In rare cases (less than 1%), pancreatitis can have a severe course and may require surgery. Other less frequent complications (with an overall incidence of less than 2%) are: infection of the biliary tract or cystic collections, bleeding resulting from papillo-sphincterotomy, and perforation of the duodenum or ducts. Infection and bleeding are generally treated medically or endoscopically; the perforation may require surgery in some cases. This registry aims to collect in a prospective and / or retrospective way the data of the ERCP procedures performed in our center by evaluating the sex, age of the patient, the reason why the patient was subjected to the examination, diagnosis, clinical risk factors and technical risk (i.e. associated with the procedure itself), if there have been complications, the type of instrumentation in use in our operating unit and / or the operators performing the examinations.