A patient with amenorrhea due to a prolactin-secreting pituitary microadenoma was treated with the antiserotoninergic drug metergoline for 8 months. The first menstruation occurred after 1 month of therapy, and it was followed by regular menses by the 3rd month. Presumptive evidence of ovulation was obtained in at least some instances by serum progesterone and gonadotropin determination. Serum prolactin was only slightly lowered by treatment. The patient had menses and possibly ovulation in the 2 months following drug withdrawal. Metergoline might restore ovarian function in hyperprolactinemic amenorrhea either by prolactin suppression or perhaps by direct stimulation of gonadotropin release.