Cholangiocarcinoma is a disease having the unfavourable prognosis and difficult to diagnose. This pathology is usually detected at the late stages of its evolution when the possibilities for its specialized treatment are virtually exhausted. In most cases, obstructive jaundice is the earliest manifestation of the disease. The standard diagnostic methods including transabdominal ultrasound study, computed tomography, magnetic resonance imaging, and endoscopic retrograde cholangiopancreatography not infrequently fail to provide all necessary clinical information. It is concluded that cholangioscopy provides a promising tool for the diagnostics of cholangiocarcinoma at the early stages of the disease.