The results indicating the same capacity of commercial "ORTHO" HCV-ELISA and "ABBOTT" HCV EIA tests in detecting antibodies to hepatitis C virus (anti-HCV-C100-3) were obtained. The study aimed at the detection in the blood serum of antibodies to hepatitis C virus (HCV) was carried out in 656 primary blood donors at the age of 18 to 53 years, 339 medical workers and 130 patients at the age of 16 to 63 years in three different haemodialysis wards of Moscow. Among 270 medical workers, anti-HCV-C100-3 were detected in 1.48%, which was similar to the findings in primary blood donors (1.37%), (p > 0.1). In a group of 69 medical workers in three haemodialysis wards antibodies to HCV were found in 10.14%. A high rate of HCV antibody detection was found in the patients of haemodialysis wards: from 30% to 49.1%.