As revealed in the present survey, during the last 3 years, against a background of decreased number of registered cases of acute hepatitis B (HB) and acute hepatitis C (HC), an increase in the proportion of patients with the chronic forms of these diseases was observed. The incidence rate of carriership of hepatitis B (HBV) and hepatitis C viruses (HCV) is many times greater than morbidity rates in acute and chronic forms of the disease. Such differences could be due to imperfect laboratory and clinical diagnosis. The registered statistics on HBV and HCV carriership included newly detected HBsAg and anti-HCV in the absence of clinical manifestations, which did not reflect the true spread of HBV and HCV in a given territory. The group of HBV and HCV carriers was found to include a considerable proportion of patients with asymptomatic form of HB and HC. It was testing for HBsAg, anti-HCV only without determination of virus replication markers (anti-HBc IgM, HBV DNA, anti-HCV IgM, HCV RNA) that seemingly determined the category of carriers greatly exceeding the true incidence. To obtain reliable epidemiological information, the complex detection of HB and HC infection markers is necessary.