New studies of breastfeeding have discovered or confirmed the benefits to mother and child. They reinforce an emphasis on exclusive breastfeeding - no other food or fluids - during the first 6 months. Studies include findings from across the world, in well-resourced and poorly resourced settings. They also emphasize longer duration of breastfeeding, into the second year of life, and gradual rather than abrupt weaning. For HIV-infected mothers, the dangers of non-exclusive feeding in the first half year of life have been well documented in recent publications. Other studies open up the possibilities for antiretroviral treatment to accompany breastfeeding, whether given to the mother, or child, or both. To be effective, implementation of any recommendations must consider individual, family, and community resources.