Chronic hepatitis C virus (HCV) infection is now the most important cause of liver cirrhosis and hepatocellular carcinoma worldwide. HCV infection prevalence is high among haemophiliacs (39%-98%), who got infected when received inadequately or non-virus-inactivated large-pool clotting factors concentrates before 1992. Current treatment reduces the probability of developing advanced stages of liver disease. The objective of this study was to evaluate efficacy and safety of the treatment with interferon alpha (IFN) and ribavirin in haemophiliacs. From July 2000 to November 2002, 18 patients were treated with IFN, three million units thrice weekly combined with daily oral doses of 1,000 or 1,250 mg of ribavirin for a minimum of 48 weeks. Eleven patients (61%) showed end of treatment virological response, while nine [(50%): 95% CI: 27-73%] showed sustained virological response as defined by undetectable HCV-RNA six months after treatment. All those nine had persistently undetectable HCV-RNA two to four years post-treatment. There was no treatment interruption due to adverse events. Therefore, the rate of sustained virological response was 50%, with good tolerance.