The present study was undertaken to investigate not only the effectiveness of bromoergocryptine therapy in 13 women with amenorrhea-galactorrhea and hyperprolactinemia without evidence of organic pathology, but also to assess the value of pretreatment evaluation in predicting the response to therapy. Sella turcica tomography, base line serum follicle-stimulating hormone, luteinizing hormone (LH), thyroid-stimulating hormone, T4, plasma cortisol levels, and the growth hormone reserve were normal in all patients. The pretreatment administration of LH-releasing factor (LRF) (100 microng subcutaneously) resulted in either a normal or excessive release of LH. On bromoergocryptine therapy, cyclic menses were reintiated in 10 of the women, while conception occurred prior to reinitiation of menses in the remaining three women. The time required for resumption of menses or conception on therapy correlated well with the magnitude of gonadotropin response to LRF. No correlation was seen with pretreatment prolactin levels nor with the degree of suppression of prolactin during bromoergocryptine therapy. In four women the mean prolactin levels during therapy were above normal, and in one patient prolactin levels approached pretreatment values during therapy. The initiation of cyclic menses despite continued hyperprolactinemia may indicate a possible direct effect of bromoergocryptine on hypothalamic LRF secretion as a partial explanation for its therapeutic action. On discontinuation of bromoergocryptine therapy, serum prolactin levels rapidly returned to pretreatment values or higher in all of the patients studied. In contrast to previous studies in which amenorrhea recurred in all patients after discontinuation of therapy, three of our patients maintained cyclic menses despite continued hyperprolactinemia. The recurrence of hyperprolactinemia after discontinuation of bromoergocryptine would indicate a persistent autonomy of the mechanisms involved. Periodic endocrine evaluation will be necessary to substantiate the presence or absence of pituitary microadenoma in these women.