Seventy-one of 84 human immunodeficiency virus (HIV)-infected children [84.5% (95% confidence interval: 75-91.5%)] were hepatitis A virus (HAV) seropositive after 2 doses of HAV vaccine. Higher CD4% and HIV suppression were significantly associated with increased HAV seropositivity rate. In multivariate analysis, CD4 >or=25% and young age were independent predictors of HAV seropositivity. Of 7 children given a third HAV vaccine dose because of negative HAV antibody after 2 doses, 2 (29%) became seropositive.