This open-label, non-randomized, single arm study will provide treatment or re-treatment with Pegasys (peginterferon alfa-2a) as monotherapy or in combination with Copegus (ribavirin) to patients with chronic hepatitis C infection. Patients who have received prior Pegasys monotherapy or combination therapy or who were considered eligible for treatment with Pegasys in previous donor protocols will be eligible to participate in this study. Treatment will be on investigator's decision according to the approved label for up to 48 weeks, with a 24-week safety follow-up.

Inclusion Criteria:

• Adult patients, ≥ 18 years of age.
• Chronic hepatitis C.
• Compensated liver disease (Child-Pugh Class A).
• Previous participation in a donor protocol in which treatment or re-treatment with Pegasys alone or in combination with Copegus was recommended or deemed appropriate after study completion.
• Have completed safety and efficacy assessments as defined in the donor protocol without violation or any major deviation.
• Have not received any other anti-hepatitis C virus treatment after the completion of the donor protocol.
• For females of childbearing potential, a negative pregnancy test within 24 hours prior to first dose of study drug.
• Fertile patients (male and female) must use 2 reliable forms of contraception (combined) for the duration of the study (treatment and follow-up) in accordance with the locally approved label for Copegus.

Exclusion Criteria:

• Pregnant or breastfeeding women.
• Male partners of women who are pregnant.
• Patients with hemoglobinopathies.
• Hepatic decompensation (Child-Pugh Class B or C) before or during treatment.
• Non-responder patients (defined as patients previously treated with Pegasys and Copegus combination therapy at standard doses for at least 12 weeks who did not achieve at least a 2-log drop from their baseline viral load).
• Liver disease other than chronic hepatitis C, including hepatic carcinoma.