Hepatitis C is found in approximately a third of patients infected with HIV. Therapy of hepatitis C in HIV patients is very important from several view points. First, hepatitis C in the setting of immunosuppression may progress faster, although recent data show that mortality from liver disease was decreased in highly active antiretroviral therapy. HIV/hepatitis C coinfection is associated with more frequent elevation in liver tests (drug-induced liver injury) during highly active antiretroviral therapy, and in some studies, hepatitis C has been associated with lower CD4+ recoveries. The therapeutic standard of care is a combination of peginterferon and ribavirin at a fixed dose, 800 mg/day, although higher ribavirin doses may further improve virologic outcomes. In patients that do not respond virologically, maintenance therapy with peginterferon monotherapy is a potential avenue to stem the advance of liver fibrosis, although controlled data in coinfected patients are needed to issue formal recommendations.