Till nowadays the diagnosis of biliary and pancreatic ducts disorders remains to be rather difficult. Cholangioscopy is the only method, that gives an opportunity of visual evaluation of the ducts. The results of 234 retrograde peroral pancreatico-cholangioscopies (RPCS) in 149 patients are analysed. 2 systems of the "Olympus" endoscopes, including both "mother" and "daughter" apparatus with uncontrolled (model PF-24, external diameter 2.4 mm) and controlled distal tip (model CHF B 20, external diameter 4.5 mm) were used for the tests. Endoscopic papillosphincterotomy has been performed in 87 of the patients, who were later on tested with RPCS (147 tests). 38 RPCS have been performed in 29 patients after transduodenal papillosphincterotomy. 47 cholangioscopic procedures have been undertaken in 31 patients after various types of biliodigestive anastomoses. In 2 cases RPCS has been performed after the balloon dilatation of the major duodenal papilla. The signs of catarrhal cholangitis have been observed in 27% of the cases. Purulent cholangitis was present in 13.4% of the patients. Cholangitis was detected in 19.5% of the cases in long-term follow up after endoscopic papillosphincterotomy; in 88.2% of such cases catarrhal inflammation of duct's mucosa was observed. It is stated that after endoscopic surgery cholangitis is observed 2.5 times less frequently, than after relevant transduodenal procedure.