Maternal milk is recommended as the optimal and exclusive source of early nutrition for all infants from birth and until at least their sixth month of age. Their nutritional virtues are due to potent immune factors and a unique composition which evolves in tandem with the infant's growth and developmental needs. Breast milk promotes sensory and cognitive development, and protects the infant against infectious and chronic diseases. Exclusive breastfeeding reduces infant mortality due to common childhood illnesses such as diarrhea or pneumonia, and improves recovery time during illness. Breastfeeding provides numerous short- and long-term health benefits for both the baby and its mother. Beyond the immediate benefits for infants, breastfeeding also contributes to a lifetime of good health. In this review we describe the influence of breastfeeding on mental and psychomotor development, on the risk of endocrine disorders, pediatric cancers and allergic diseases for the breastfed child. More prospective studies with comparable methodologies and longer periods of follow-up are necessary to allow firm conclusions on the effects of breastfeeding in some of these aspects.