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 HIVinfected 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<0.001). Children in the HIV-infected group had lower mean psychomotor scores than the HIV-exposed children and the reference group. In the HIV-infected group, disease stage was a negative predictor and weight for age a positive predictor of psychomotor outcome. INTERPRETATION Weight for age and disease stage provide viable, easily measurable benchmarks to specify when frequent developmental monitoring and psychomotor rehabilitation are required. Nutritional intervention and other measures aimed at slowing disease progression may delay the onset and severity of psychomotor impairment in the paediatric HIV population in Africa.