We conducted a matched case-control study of 566 HIV-infected children in Botswana during a 2009-2010 measles outbreak to identify the risk factors for measles. Children in the oldest age quartile (≥13.1 years) were 4-fold more likely to acquire measles than those in the youngest quartile (<7.1 years). HIV-infected older children and adolescents may benefit from additional measles vaccination.