In industrialized countries HIV-1-seropositive mothers who are nursing infants are advised to use artificial feeds, whilst HIV-infected women in the developing world are recommended to breast-feed. Current evidence is insufficient even to estimate the attributable risk associated with breast-feeding. There is a possibility that the policy promoted in industrialized societies will eventually become established in urban and peri-urban areas of sub-Saharan Africa. This may be defensible for some elite urban mothers providing safe artificial feeding. However, calculations of the consequence of any population-level change to bottle-feeding indicate that it would result in more deaths from infectious causes, substantially adding to the child deaths directly attributable to HIV-1 infection. These data demonstrate that there is a clear need for policy-makers and health care workers to undertake further promotion of breast-feeding despite the AIDS epidemic.