BACKGROUND AND AIM: Large interferon-based therapeutic trials are still lacking in children with hepatitis C and the long-term safety and efficacy of interferon is unknown. This study describes the outcome of hepatitis C in 43 children enrolled in an oper-label interferon trial, and were followed up to 66 months after stopping treatment. PATIENTS AND METHODS: All patients received interferon alfa2a (5MU/m(2)) thrice weekly for 6 moths, children with genotype 1b received 3MU/m(2) thrice weekly for 6 additional months. RESULTS: Nine children discontinued interferon for adverse events and three were not compliant to treatment. Eitht (19%, intention to treat analysis), including 2/20 (10%) with genotype 1b and 6/12 (50%) with genotype 2 or 3, were sustained responders 12 months after stopping therapy. During further follow-up (mean+/-S.D.: 44.7+/-14.6 months), response was maintained; two non-responders cleared viremia, while a young boy progressed to cirrhosis. CONCLUSIONS: Small sample size an therapy withdrawal are the major limitations in the interpretation of our results. Nevertheless, our data, suggesting that response to interferon in children with hepatitis C is genotype-related and stable, agree with the results of large studies in adult. The outcome in non-responders was variable, including persistence of viremia and mild-moderate cytolysis (most cases), progression to cirrhosis, or eventual sustained viremia clearance.