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.