There are no data regarding HCV prevalence in CRF patients not requiring dialysis. In order to assess prevalence and risk factors for HCV infection in CRF patients on conservative therapy we tested, by second-generation assays such as Ortho 2 and 4-RIBA, 221 predialysis CRF patients attending our Department. Forty-four (20%) patients were anti-HCV positive. Anti-HCV positivity was related to blood transfusion requirement, past or current elevations of transaminase levels and, to a lesser degree, CRF duration. The prevalence of anti-HCV positivity among CRF patients who were never transfused was about 10 times higher than that of blood donors. Our data show that predialysis CRF patients should be considered a specific risk group for HCV infection; blood transfusion history and duration of CRF are risk factors for acquisition of HCV infection; HCV infection may play a role in the development of liver disease in this clinical setting.