This is a multicenter clinical trial designed to compare the efficacy of 48 weeks of therapy with pegylated (PEG)-Interferon/ribavirin in Southeastern Asian patients with genotype 1 chronic hepatitis C with 48 weeks of therapy with PEG-Interferon/ribavirin in Caucasian patients with genotype 1 chronic hepatitis C. This study is also designed to provide a randomized comparison of 24 weeks versus 48 weeks of therapy with PEG-Interferon/ribavirin in Southeastern Asian patients with genotypes 6-9. The primary endpoint is sustained virologic response, as defined by negative hepatitis C virus (HCV) ribonucleic acid (RNA) in serum at 24 weeks after therapy completion.