Anti-HCV was tested in 77 uremic patients, 48 on hemodialysis (HD), 29 on CAPD, by immunoenzymatic 1st and 2nd generation assays (ELISA I, II) and 4-antigen (4-RIBA) immublotting. The investigation was extended to the staff (n = 29) and to HCV-positive patients’ families (n = 30). The prevalence using 2nd generation tests was double (21%) that in 1 st generation tests (11%). A greater incidence in the HD than in the CAPD group (23 vs. 17%) and a highly significative correlation to dialytic age were observed. No one among the sanitary personnel and only 2 family members were found HCV positive, suggesting a low infectivity via the parenteral inevident route. Extracorporeal circulation and particularly the exposure time to the treatment seem to be the main risk factors.