The authors review the research literature on breastfeeding benefits and promotion. Although breastfeeding confers numerous benefits to infants, mothers and society, the authors conclude that breastfeeding promotion efforts sometimes overstate or misrepresent what the research actually supports about the benefits of breastfeeding. Psychological or cognitive benefits, particularly for full-term healthy infants, may be overstated. In some studies, variables such as income, education and maternal IQ are not adequately taken into account. Studies that do take these variables into account often find little or no association between breastfeeding and cognitive outcomes except in the case of premature or low birth weight infants. Although often promoted as a benefit of breastfeeding, there is little support of the assertion that breastfeeding enhances bonding between mothers and their infants. It is important that breastfeeding promotion efforts are accurate, appropriate to the audience and address barriers to breastfeeding.