The clinical use of anti-dopaminergic drugs to stimulate plasma PRL levels, to induce lactogenesis and maintain an adequate lactation has been widely suggested, taking into consideration the main inhibitory role of hypothalamic dopamine on PRL secretion. We therefore studied the effects of domperidone (DOM), a direct anti-dopaminergic drug with a low tendency to be secreted in the milk and which does not cross the blood-brain barrier, on inducing lactogenesis in 8 puerperal women with a history of defective lactogenesis (group A) and inducing galactopoiesis in 9 puerperal women who showed 2 weeks after delivery an insufficient lactation (group B). A placebo treatment was performed in 7 and 8 puerperal women with the same characteristics of group A and B, respectively. PRL plasma levels were assayed in basal conditions and after suckling from the 2nd to the 5th day of puerperium in group A and through a 10-day treatment in group B. In both groups domperidone-treated subjects always showed baseline PRL levels and daily milk yield significantly higher than those of the placebo group (P less than 0.01). The lack of any side-effects and the positive results suggest a high usefulness of such a drug in inducing and/or maintaining successful breast feeding, which is at present considered so important for a healthy development of infants.