The article presents the results of our own research on the features of the clinical course of chronic hepatitis C (HCV) in HIV-infected patients at various stages, the disease of which proceeded against the background of drug addiction. CGC was clinically characterized by the absence of vivid symptoms of hepatitis, masked not only by the symptom complex of drug addiction, but also by the concomitant pathology that determines the symptoms of HIV infection in the stage of secondary diseases. Chronic hepatitis C against the background of drug addiction is characterized by early reactivation with manifestation of hepatic and extrahepatic manifestations (asthenovegetative and dyspeptic syndromes, hepatomegaly, arthralgia), on which the symptom complex of neurological and somatic disorders inherent in drug addiction is superimposed, and is accompanied by greater activity of the liver process. It has been established that the ability of HIV infection to accelerate the natural course of HCV infection due to progressively developing immunodeficiency due to HIV.