We carried out a retrospective study to analyze the long-term response to highly active antiretroviral therapy of 19 vertically human immunodeficiency virus type 1/hepatitis C virus (HCV-1/HIV) coinfected children. The clinical, immunologic, viral, and biochemical variables were assayed at 0, 1, 2, 3, 4, 5, and 6 years of follow-up. Our data suggest that CD4 T-cell recovery and viral load control during long-term highly active antiretroviral therapy among HIV-1/HCV children were similar to those described in HIV-1 monoinfected children, but hepatic function was significantly altered in HIV-1/HCV children.