Since human prolactin was isolated and characterized 13 years ago, the study of the control of prolactin secretion has been intensive. Hyperprolactinaemia is the most commonly identifiable hypothal amic pituitary disorder1,2. The dominant inhibitory nature of hypo thalamic control of prolactin secretion may be the reason that hyperprolactinaemia is such a common condition. During the PClst decade two separate therapeutic approaches to the management of hyperprolactinaemia have been introduced: transsphenoidal selec tive pituitary microsurgery and medical therapy to suppress prolactin secretion with orally active long-acting dopamine agonist drugs. Small prolactin-secreting tumours are treated extremely satisfactorily both with medical and with surgical therapy, both in terms of lower ing serum prolactin levels to normal and in restoring gonadal func tion. However, for the larger tumours, either where the tumour is invasive or the pretreatment serum prolactin level is greater than 1 250ngml- the results of surgery are poor in terms of restoring to normal circulating prolactin levels and gonadal functionJ-s. We now discuss the medical management of hyperprolactinaemia, potential problems during pregnancy and the management of large prolactin secreting pituitary tumours.