The interleukin (IL)-4 -589-C/T polymorphism has been reported to protect against human immunodeficiency virus type 1 (HIV-1)-related disease progression in white adults. In the present study, the effect of the IL-4 -589 polymorphism on HIV-1-related disease progression was evaluated in a seroprevalent cohort of 1043 children. The IL-4 -589-T allele was more prevalent in Hispanic and in black, non-Hispanic children, compared with white, non-Hispanic children. We found that the IL-4 -589-C/T polymorphism does not affect the risk of HIV-1-related disease progression or central nervous system impairment in children, and this did not differ by race/ethnicity. Our findings suggest that the IL-4 -589-C/T polymorphism is not an important determinant of HIV-1 disease progression in children.