The agent of the majority of parenterally transmitted non-A, non-B hepatitis is the hepatitis C virus (HCV). In this study, we estimate the HCV seropositivity in 7,771 blood donors and 317 patients on hemodialysis in 5 different centres, of which 4 are situated in Beirut. The used screening test consists of a second generation EIA technique. The study shows that 0.41% of blood donors are HCV seropositive. The mean percentage of seropositive patients is about 27% but the comparison of centres among them showed a high variability (10, 19, 21, 33 et 39%). The blood transfusion, the number of years on hemodialysis and the screening of blood donors seem to be the main risk factors. Reducing the number of transfusions to hemodialysed patients and screening antibodies anti-HCV in blood donations are primordial.