AIM To report on the efficacy, safety and tolerability of interferon alfa-2a combined with a "low dose" of ribavirin for relapsers and non responders to alpha interferon monotherapy.METHODS Thirty-four chronic hepatitis C virus-infected non-responders to interferon alfa2a monotherapy (a course of at least 3 months treatment) and 13 relapsers to interferon alfa 2a monotherapy (a dose of 3 to 6 million units three times per week for at least 20 weeks but not more than 18 months) were treated with the same dose of interferon alfa-2a used before (3 to 6 million units three times per week) and ribavirin (10 mg/ kg daily) for 6 months. In complete responders, interferon alfa-2a was administered for further 6 months at the same dose used before as monotherapy.RESULTS Seven (20.6%) of 34 non-responders stopped the combined therapy due to adverse events, including two patients with histological and clinical Child A cirrhosis. In 17/27 (63%)non-responders, the combined therapy was stopped after three months because of non-response. Ten of the 27 non-responders completed the 1;2-month treatment course. At a mean follow up of 28 months (16- 37 months)after the treatment, 4/10 (15%) previous non-responders still remained complete responders,All 13 previous relapsers completed the 12-month treatment course. At a mean follow up of 22months (9 - 36 months) after treatment, 6/13(46%) the previous relapsers were stillsustained complete responders.CONCLUSION Our treatment schedule of the combined therapy for 6 months of interferon alfa2a with a low dose of ribavirin (10 mg/kg/day)followed by 6 months of interferon alfa-2amonotherapy is able to induce a sustainedcomplete response rate in 15% of non-responders and 46% of relapsers with chronic hepatitis C virus-related liver diseases comparable to those obtained with the standarddoses of ribavirin 1000 - 1200 mg/day.Randomized prospective controlled trials using lower total amounts of ribavirin in combination with interferon should be performed.