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.

Post-marketing surveys are not considered applicable clinical trials and thus the results of this survey will not be posted at its conclusion. The results will be submitted to public health officials as required by applicable national and international laws.

Inclusion Criteria:

• Patients diagnosed with chronic hepatitis C
• Among interferon-naïve patients, only patients with high viral load and HCV genotype other than 1
• Among prior nonresponders or relapsers to interferon monotherapy, (1) patients with high viral load and HCV genotype other than 1; and (2) patients with low viral load of all genotypes (including genotype 1)

Exclusion Criteria:

• Patients infected with HCV genotype 1 with high viral load, regardless of whether treatment-naïve or previous nonresponders/relapsers
• Interferon-naïve patients with low viral load
• Patients with a history of hypersensitivity to test drugs or other interferon preparations
• Patients with a history of hypersensitivity to biological products, such as vaccines
• Patients being treated with Shosaikoto
• Patients with autoimmune hepatitis
• Pregnant women, women who may be pregnant, and nursing mothers
• Patients with a history of hypersensitivity to any component of this drug or other nucleoside analogs (aciclovir, ganciclovir, vidarabine, etc.)
• Patients with difficult-to-control cardiac disease (eg, myocardial infarction, cardiac failure, arrhythmia)
• Patients with hemoglobinopathies (eg, thalassemia, sickle-cell anemia)
• Patients with chronic renal failure or renal function disorder with creatinine clearance of <=50 mL/min
• Patients with or a history of severe psychiatric condition such as severe depression, suicidal ideation or suicide attempt
• Patients with serious hepatic dysfunction
• Patients with autoimmune hepatitis

Patients with chronic hepatitis C excluding subjects with HCV genotype 1 and high viral load, and interferon-naïve subjects with low viral load. Patients undergoing treatment with PegIntron and Rebetol in clinical practice at approximately 50 to 100 sites in Japan.