Human immunodeficiency virus-1 (HIV-1) associated central nervous system disease may complicate the course of HIV-1 infection in infants and children. Neurologic dysfunction in these young patients adds significantly to the morbidity of the disease and is often a devastating complication. It is apparent that HIV-1 infection in infants and young children is complicated by numerous developmental parameters. The developmental stage of the nervous and immune systems when exposed to the virus is likely to interact in complex ways with HIV-1 variables. In order to care for these children and to design rational approaches for treatment and prevention, it is now critical to develop a better understanding of how HIV-1 affects the developing nervous system.