Thirteen Japanese children and young adults (age range 10-40 years, median 18 years) with chronic hepatitis C have been treated with pegylated interferon α2b and ribavirin combination therapy in our pediatric center. The HCV RNA levels before treatment were 5-3,900 KIU/ml (median 1,500 KIU/ml), with HCV genotype 1 in 7 patients, 2a in 5, and 2b in 1. Of the 13 patients, 8 have completed the treatment course with sufficient follow-up to date, and 7 (with HCV genotype 1b in 4, 2a in 2 and 2b in 1) of them (88%) have achieved sustained virological response. The major adverse effect related to therapy was fever. This combination therapy was well tolerated in all the patients without cessation of the therapy. Our present results encourage treatment of pediatric hepatitis C patients with pegylated interferon and ribavirin, as in adult patients.