A 15-year-old girl with perinatal HIV-1 infection has remained asymptomatic with undetectable plasma HIV-1 viremia for more than 5 years after discontinuing all antiretroviral therapy. Viral sequence analysis of proviral HIV-1 DNA revealed no evident fitness-attenuating deletions or mutations. This subject exhibited an unusually robust HIV-specific T-cell response, with an intact CD4+ T cell–proliferative response to HIV-1 antigens. In addition, the subject was found to be heterozygous for the 32-bp deletion in the CCR5 gene, which encodes the primary coreceptor for HIV-1 entry into cells. This mutation mediates profound resistance to HIV infection in homozygotes and has been associated with delayed disease progression in heterozygotes after both horizontal and vertical HIV-1 infection. Although adults with long-term nonprogressive HIV disease have been studied at length, there is no prior description in the literature of a perinatally HIV-infected child whose plasma HIV-1 viremia is controlled to undetectable levels in the absence of antiretroviral therapy.