Children infected with human immunodeficiency virus (HIV) are at particular risk for psychological disturbance. Little is known about the mental health status of children on highly active antiretroviral therapy (HAART). A hospital-based cross-sectional study of 318 children aged 6-14 on HAART in Addis Ababa was conducted. Behavioral and emotional problem was assessed using the child behavior check list (CBCL/6-18). Logistic regression analysis was done to select the best subset of predictor variables and determine their association with behavioral and emotional problems. Of the 318 caregivers of children aged 6-14 on HAART, 39.3% of the children had behavioral and emotional problems. Low family monthly income (AOR, 3.44, 95% CI, 1.89-6.25), older age (AOR, 2.27, 95% CI, 1.34-3.83), and parental loss (AOR, 1.89, 95% CI, 1.10-3.25) were found to be determinants of behavioral and emotional problems in the multivariate logistic regression. There is high prevalence of behavioral and emotional problems in children on HAART in Addis Ababa. More support is needed to children from families of low income and those who lost their parents. Further research should be carried out to enhance better understanding and appropriate response to behavioral and emotional problems.