Ten patients with chronic hepatitis C, six of whom had not responded and four of whom had responded in a non-sustained fashion to interferon-alpha treatment alone, were given interferon alpha-2b and ribavirin in combination during 24 weeks. Interferon alpha-2b was given subcutaneously, at a dose of 3 MU thrice weekly, together with ribavirin orally, at a dose of 1,000-1,200 mg/day. All four patients with a prior non-sustained response to interferon alone had normal alanine aminotransferase (ALT) levels at the end of treatment as well as during follow-up (> or = 24 weeks post treatment). Furthermore, all four lost serum HCV-RNA at the end of treatment and three continued to be negative during follow-up. Among patients with a prior non-response to interferon alone three of six had normal ALT levels at the end of treatment and one at follow-up. Two of six became HCV-RNA negative at cessation of treatment, one of whom was negative also at follow-up. All former non-sustained responders and one of six non-responder patients thus showed a sustained biochemical response with eradication of HCV-RNA from serum in all cases but one. It is concluded that combination therapy with interferon alpha-2b and ribavirin offers a chance of sustained biochemical response with eradication of the viremia in patients who have not shown a persistent response to interferon-alpha alone.