Disease progression in children acquiring HIV infection vertically from their mothers is more rapid in developing countries compared with developed countries. The probability of death by 12 months in sub-Saharan Africa ranges from 0.23 to 0.35, and by 5 years is 0.57-0.68. Data from Europe in the era before highly active anti-retroviral therapy (HAART) yielded probabilities of 0.1 and 0.2, respectively. Confirming the diagnosis can be difficult in resource-limited settings. Existing clinical case definitions are useful epidemiologically, but of low positive-predictive value in individual children. Priorities for research into management issues include nutrition (infant feeding, vitamin A and micronutrient supplementation), prophylaxis against Pneumocystis carinii pneumonia (PCP), and bacterial infections, case management of persistent diarrhoea, diagnosis/prevention/management of tuberculosis in children and prevention of sexual transmission in adolescents.