Mother-child interaction is usually described in psychological terms; however, it is becoming increasingly clear that neuroendocrine mechanisms are involved in the mother-child interaction. Mother and fetus influence each other by hormonal mechanisms in utero, and after birth, mother and child interact by way of sensory stimulation. In the breastfeeding situation, the infant's suckling stimulates maternal oxytocin and PRL release and, thereby, milk production and release. In addition, oxytocin, by way of circulating and central neurogenic oxytocinergic mechanisms, adapts maternal physiology and endocrinology to allow milk production. At the same time, suckling influences the physiology and endocrinology of the infant to optimize the growth process. It seems that tactile, olfactory, visual, and perhaps other types of sensory stimuli contribute to the adaptive changes in both mother and infant. In addition, behavioral changes are induced in the mother in connection with birth and breastfeeding. Data are accumulating that suggest that the attachment between mother and infant is facilitated by skin-to-skin contact early postpartum. Furthermore, calm and social interactive behavior is promoted in the mother. Central oxytocinergic mechanisms activated in connection with birth and breastfeeding seem to be involved in the behavioral changes.