There is consensus on the benefits for all infants of exclusive breastfeeding for 6 months and introduction of appropriate complementary foods at 6 months, followed by continued breastfeeding. However, guidelines on infant and young child feeding (IYCF) for HIV-positive mothers have changed continually since 2000. This article explores issues and evidence related to IYCF for the prevention and care of paediatric HIV in resource-limited settings in light of new HIV treatment guidelines, implementation challenges and knowledge gaps.In 2010 the impact of antiretroviral drugs (ARVs) on reducing the risk of mother-to-child transmission of HIV moved WHO to urge countries to endorse either avoidance of all breastfeeding or exclusive breastfeeding for the first 6 months while taking ARVs, depending on which strategy could give their infants the greatest chance of HIV-free survival. Implementation of the 2010 recommendations is challenged by lack of healthcare provider training, weak clinic–community linkages to support mother/infant pairs and lack of national monitoring and reporting on infant feeding indicators.More evidence is needed to inform prevention and treatment of malnutrition among HIV-exposed and HIV-infected children. Knowledge gaps include the effects of prolonged ARV exposure, the cause of HIV-associated growth faltering, the effects of early infant testing on continuation of breastfeeding and specific nutrition interventions needed for HIV-infected children.Significant progress has been made toward keeping mothers alive and reducing paediatric HIV infection, but sustained political, financial and scientific commitment are required to ensure meaningful interventions to eliminate postnatal transmission and meet the nutritional needs of HIV-exposed and HIV-infected children.