Antiretroviral therapy contributes to decreasing morbidity and mortality, and ultimately to increasing survival. In Brazil, there are regional differences in HIV epidemiology regarding pregnant women and children with HIV/AIDS. This study evaluates survival time after AIDS diagnosis in 914 children infected by mother-to-child transmission, reported between 1983 and 1998 and followed until 2002, in Brazil's five regions. Time between birth and HIV diagnosis decreased over the years, mainly in the South and Southeast Regions. There was a significant improvement in survival; more than 75% of cases were still living four years after diagnosis in the 1997-1998 group. This Brazilian study demonstrates that even with regional inequalities in health care infrastructure it is possible for a developing country to establish an effective system of universal and free access to antiretroviral therapy that produces a significant increase in survival for children with AIDS.