Treatment of chronic hepatitis B and C aims to achieve viral eradication. Decreasing the number of carriers subsequently reduces the transmission of the viruses. For an individual patient, therapy is aimed at preventing cirrhosis, liver failure and hepatocarcinoma. Among potential therapies, interferon alfa offers the best results. In one study involving the treatment of children from a region of intermediate endemicity, interferon alfa accelerated the clearance of hepatitis B virus (HBV) replication. In long-term follow-up, the study did not show a significant difference between patients who were treated and those who were not in the rate of disappearance of serum HBV-DNA, normalization of alanine aminotransferase (ALT) levels or seroconversion to antibodies to hepatitis B e antigen. The most important factors in predicting a rapid decrease in HBV replication were AI T levels more than twice normal, low levels of serum HBV-DNA (less than 100 pg/mL) and inflammatory activity on liver biopsy (chronic active hepatitis). A select group of children with HBV infection has thus been shown to benefit from interferon alfa therapy. Treatment should be administered in a dosage of 6 MU/m2 three times each week for 6 months. Chronic active hepatitis, develops in approximately 30% of children with a chronic hepatitis C virus (HCV) infection. Cirrhosis due to HCV appears to be a very rare complication among children. Results of interferon alfa treatment for children with HCV are scarce. A pilot study of 12 children treated with interferon alfa in a dosage of 3 MU/m2 three times each week for 6 months showed that ALT levels normalized in approximately 90% of the patients after 15 months of follow-up. All of the patients had a decrease in the histological activity of the disease. Factors predictive of a favourable response in adults were: low levels of gamma-glutamyl transferase, young age, female sex, short duration of disease, absence of cirrhosis and low histological activity of the disease. Controlled randomized studies are needed to determine the indications for interferon alfa therapy in children infected with HCV. Available data suggest that children may have a better response than adults.