This multi-center, observational study will examine the clinical use and outcomes of pegylated interferon (PEG-IFN) alfa-2a and ribavirin combination (PEGASYS RBV) in participants with chronic hepatitis C (CHC). Study visits will be scheduled for baseline, 12, 24 and 48 weeks after baseline. An additional follow-up visit at week 72 will be required for participants with an HCV genotype other than 2 or 3. Quality of life data will be collected at baseline, and at each follow-up visit.

Inclusion Criteria:

• Eligible for and scheduled to receive treatment with commercially available PEG-IFN alfa-2a and ribavirin combination
• Serologic evidence of chronic hepatitis C (CHC) infection
• Detectable serum hepatitis C virus - ribonucleic acid (HCV-RNA)
• Negative urine or blood pregnancy test
• Fertile participants receiving treatment to use two forms of effective contraception during treatment and for 6 months after treatment end

Exclusion Criteria:

• Women with ongoing pregnancy or who are breast feeding, or male partners of women who are pregnant
• Received any investigational drug less than or equal to (</=) 6 weeks prior to enrollment
• Moderate hepatic failure [Child-Pugh greater than or equal to (>/=) B]
• Co-infection with human immunodeficiency virus (HIV) or hepatitis B
• Autoimmune hepatitis
• Known hypersensitivity to alfa interferons, E. coli-derived products, polyethylene glycol, ribavirin and/or any ingredient in the formulation or component of PEG-IFN alfa-2a or ribavirin

Participants with hepatitis C, who were to be treated with combination of pegylated interferon (PEG-IFN) alfa-2a and ribavirin (PEGASYS RBV), within 7 days of baseline.