The bile duct tumors diagnostics is very challenging due to the long asymptomatic course of the disease, complexity of early diagnosis and morphological verification of oncological process. In the vast majority of cases, the development of obstructive jaundice and the absence of pain syndrome are the only reasons that make it possible to suspect intraductal cholangiocarcinoma. CT, MRI and US examinations make it possible to suspect the localization of the tumor process in proximal regions and confluence of bile ducts. Morphological confirmation of the diagnosis can be obtained by performing a blind biopsy during ERCP and by performing intraoperative or oral cholangioscopy. The results of Klatskin tumor surgical treatment are unsatisfactory and tend to have high mortality rates. Chemotherapy and radiotherapy also do not meet the modern requirements of treatment. Oral cholangioscopy makes it possible to differentiate genesis of extrahepatic bile duct strictures with high accuracy, to perform targeted biopsy and to conduct a photodynamic therapy, which has shown high efficiency according to foreign studies. It the first time in Russia the authors have applied photodynamic therapy method using digital video choledochoscope of SpyGlass™ DS technology to treat a patient with Klatskin tumor.