Breastfeeding is nature's effective method of child-spacing, provided that feeding is exclusive and prolonged. Yet, its popularity has been limited in modern societies for a range of cultural, social and medical reasons. It is a matter of surprise and regret that no medical specialty has claimed overall 'ownership' of the physiology, function, pathology and management of this conspicuous organ, the female breast. The breast has major benefits for the baby in protecting against debilitating diarrhoea, necrotising enterocolitis and certain allergies, as well as providing highly specific nutritional requirements for the human neonate. It is less widely appreciated that, in addition to its major child-spacing benefits for the mother, breastfeeding also provides major protection against the development of breast cancer, up to 50% reduction in incidence in one study. Few other measures can approach this.