The survival chances of preterm infants have improved considerably in the last few decades. The advantages of giving breast milk to neonates and infants for a sufficiently long period using this as the sole feeding method as far as possible have been sufficiently demonstrated. At least for preterm infants, breast milk is additionally an urgent medical and thus simultaneously a therapeutic intervention: it significantly reduces the typical morbidity of these children, increases the survival rate and improves long-termoutcomes. This book aims to summarise theoretical principles of breastfeeding in preterminfants and neonates and their practical implementation in the difficult everyday setting of a neonatology unit. But it also attempts to define the context and framework conditions in which it is possible to also feed very small preterminfants using their mother's milk as exclusively as possible and for a sufficiently long time, specifically through breast-feeding. International authors from very different professions convey their expertise to give the very smallest babies the best chances for their long-termdevelopment and moreover to provide food for thought about moving away from traditional strategies of feeding and behaviour.