The objective of the study is to evaluate the safety and efficacy of PegIntron plus Rebetol combination therapy administered to patients with chronic hepatitis C. The study will exclude (1) subjects with HCV genotype 1 and high viral load, and (2) interferon-naïve subjects with low viral load. It is being conducted as a post-approval commitment, in accordance with the Ministry of Health, Labour and Welfare's guideline on Good Post-marketing Study Practice.