Introduction: The hepatitis C virus (HCV) infection is usually asymptomatic and has a high rate of chronicity, which may progress to cirrhosis and hepatocellular carcinoma. The hepatitis C diagnosis is realized by antibodies research using ELISA test (Enzyme Linked Immunosorbent Assay) and confirmed by additional serological tests, such as RIBA (Recombinant Immunoblot Assay) and western blot, and confirmatory test, like HCV-RNA research. The objective of this study was to evaluate the RIBA efficacy in the diagnosis of HCV infection in blood donors with anti-HCV reagent.