AIM: We aimed to investigate the contribution of disease stage and weight for age to the variability in psychomotor outcome observed among children with human immunodeficiency virus (HIV) infection. METHOD: This cross-sectional study involved 48 Kenyan children (20 females, 28 males) aged 6 to 35 months (mean 19.9mo SD 8.9) exposed prenatally to HIV. Two subgroups of HIV-exposed children were seen: those who were HIV-infected and those who were uninfected. The reference population was composed of 319 children (159 females, 160 males) aged 6-35 months, (mean age = 19 months, SD=8.43) randomly selected from the community. Disease stage varied from stage 1 to stage 3, reflecting progression from primary HIV infection to advanced HIV infection and acquired immune deficiency syndrome. A locally developed and validated measure, the Kilifi Developmental Inventory, was used to assess psychomotor development. RESULT: Using age-corrected psychomotor scores, a significant main effect of HIV status was observed (F((2,38.01))=7.89, p