Hepatitis C virus (HCV) infection is a significant worldwide health care problem. Nearly one-third of all patients infected with human immunodeficiency virus (HIV) are coinfected with HCV. Compared with HIV-monoinfected persons, coinfected individuals experience more rapid progression of fibrosis and higher incidence of cirrhosis and death as a result of liver disease. Treatment for HCV infection includes ribavirin (RBV) plus interferon alfa (IFN-alpha) or pegylated IFN, a combination treatment associated with anemia that may require RBV dose reduction or discontinuation. IFN-RBV-associated anemia is more profound among coinfected patients, who have a high prevalence of pretreatment anemia and may also be taking other medications causing anemia. Epoetin alfa administration to HCV-infected patients with IFN-RBV-related anemia can significantly increase hemoglobin levels and maintain significantly higher RBV doses compared with patients treated with RBV dose reduction alone. Higher RBV doses and adherence to HCV therapy have been associated with higher sustained virologic response (SVR) rates. Maintenance of RBV dose with epoetin alfa may improve adherence, thereby affecting SVR.