Management of HCV infection and related liver disease with treatment currently available lead to a sustained virological response in 20% of patients using interferon (IFN)-alpha mono-therapy and approximately 40-45% in those on combination therapy with ribavirin.The aim of the present investigation was to compare the effect of consensus interferon alphacon-1 (C-IFN), and IFN-alpha 2b plus ribavirin, in patients relapsing after treatment with interferon alone. A total of 112 randomised patients with relapsing HCV infection (M/F=53/59), were treated for 24 weeks with: (A) IFN-alpha 2b starting with 5/6MU/day till negativity of HCV-RNA followed by 3MU every other day, plus ribavirin 15mg/kg/day (n=34); (B) C-IFN 9microg/day (n=40); (C) ursodeoxycholic acid (UDCA; sodium salt) 450mg/day (n=37). At the end of treatment, patients were observed at follow-up for 24 weeks.Clearance of HCV-RNA was achieved by the end of treatment in 23 patients (68%) in Group A and 21 also showed a biochemical response with normal ALT; in Group B, 33 patients (82%) had both a virological and a biochemical response; in Group C, one patient cleared HCV-RNA. At the end of follow-up (sustained-response), 29% of patients in Group A (n=10/34) had negative PCR (seven patients relapsed at the 4th week, six at the 12th); in Group B, a sustained response was achieved in 58% (p<0.03; two patients relapsed at the 4th week, three at the 12th and five at the 24th).MAJOR SIDE EFFECTS COMPRISED: neutropenia (n=17) and decrease in Hb>1.5g/dl (n=33) in Group A, recurrence of psoriasis in two patients in Group B and abdominal discomfort and diarrhoea in 11 patients in Group C.Rapid clearance of circulating HCV-RNA was induced by C-IFN (66% at three weeks, 71% at six weeks): this was a good prognostic index both for end of treatment and sustained response. Treatment with C-IFN lead to a higher response rate compared to that of recombinant IFN-alpha 2b in association with ribavirin. The action of C-IFN is superior in the time taken to reach the maximal response rate during treatment and in the lower prevalence of relapse of the infection.