Hepatitis C virus is one of the most spread and dangerous human pathogens. In most cases hepatitis C develops into chronic diseases which in many cases escape antiviral therapy and is associated with contributed to progression of various virus-associated organ damage and disorders including liver fibrosis, steatosis and hepatocellular carcinoma. Many of these diseases are currently linked to oxidative and ER stresses induced by the viral proteins. At the same time, hepatitis C virus disturbs systems protecting cells from these stresses, thus avoiding their effect on processes of the virus life cycle. Here, we have analyzed recent data on mechanisms of the cellular defense system functioning in infected and uninfected cells. In addition, major data on the hepatitis C virus genome structure and main functions of the virus proteins have been summarized briefly.