The hepatitis C virus (HCV) is a leading cause of chronic liver disease, cirrhosis, and hepatocellular carcinoma and is also a common indication for liver transplantation. Interferon alfa monotherapy leads to a sustained virologic response in only 10% to 15% of HCV-infected patients. The sustained virologic response rates can be increased to approximately 40% with interferon alfa-2b and ribavirin combination therapy for up to 48 weeks. However, recent clinical trials demonstrated that pegylated interferon in combination with ribavirin can improve the response rates even further, with more than 50% of patients having a sustained virologic response to treatment. Although new therapies are emerging, significant progress must be made to reduce the morbidity and mortality from HCV infection.