A 73-year-old man turned to MC Erebouni, he had complaints for a month, in particular, general weakness, weight loss. Dark urine, yellowing of the skin and sclera, general weakness are also noticed. All the necessary examinations were carried out. As a result of a complete CT angiography of the organ systems, biliary hypertension was diagnosed in the proximal third of the common bile duct, a tumor with a diameter of 1.5-2.5 cm with the inclusion of a bifurcation of the right hepatic ducts. Immediately after the diagnosis of cholangiocarcinoma, a consultation- Tumor Board was held by leading specialists, headed by Deputy Director of Surgery Dr. Ara Vardanyan and Deputy Director of Oncology Dr. Haykui Geokchyan. A special treatment tactic was chosen, taking into account the location of the tumor, it was decided to carry out treatment in two stages: discharging of the biliary tract and then removal of the tumor. The surgery was performed by Dr. Ara Vardanyan with a team of surgeons. Percutaneous transhepatic drainage of the hepatic ducts was performed using ultrasound. After drainage of the hepatic ducts, an MRI examination confirmed the diagnosis of Klatskin tumor. At the second stage, resection of the common hepatic duct, resection of the VI segment of the liver, cholecystectomy, lymphodissection, formation of biliary-enteric anastomosis according to Rui was performed. In the postoperative period, dynamic monitoring was carried out, appropriate medical treatment was carried out and the patient was discharged with improvement.