Fifty-five patients with antibodies to HCV and chronic liver disease have been enrolled in the study. Thirty-four patients were treated with recombinant alpha interferon (IFN, 3 MU daily for 10 days followed by 3 MU twice/week for 3 months), and were compared to 21 untreated controls. Alanine aminotransferase (ALT) normalization was observed in a significant proportion of treated patients (52.9%), but 66.6% of them experienced a relapse after discontinuation of the therapy. The evaluation of the early ALT behavior after the 10 days priming with daily IFN administration was useful in predicting the response. The administration of a second IFN course with the same schedule and duration as the first course did not increase the efficacy of the treatment. Increased dosage and/or prolonged administration are probably required.