The pediatrician plays a crucial role in the success of breast-feeding by providing well-researched, practical advice and support to the lactating woman, beginning in the prenatal period and continuing until total weaning. The pediatrician can provide much needed support and affirmation when the mother is sabotaged by well-meaning friends and relatives who are misinformed about the value or techniques of breast-feeding. Mothers state that their pediatrician is the most important member of the support team but also the one most apt to obstruct success with inappropriate advice. An understanding of lactation as a physiologic process will provide a sound basis for anticipatory guidance.