A general overview of HIV infection/AIDS in the pediatric population, in Mexico, is provided. The principal categories of transmission in our country are: 45.5% perinatal, 44.0% following transfusion for hemophilia or for other reasons, and less frequently sexual transmission. In the United States and Europe, similar patterns are seen with perinatal transmission being the most important route, at higher percentages than ours. The number of cases of HIV infection in children continues to grow worldwide, primarily reflecting the problem in the adult population.