This study was carried out to further characterize the pituitary-adrenal androgen responses of hyperandrogenic patients with 'classic' polycystic ovary syndrome (PCO) and others who were less distinctive and have been called 'PCO-like'. PCO-like patients differed from PCO only in that serum luteinizing hormone (LH) levels were normal and anovulation was not consistent. Ovine corticotropin-releasing factor (CRF) resulted in normal responses of adrenocorticotropic hormone and cortisol in the two groups when compared to controls, while androstenedione (delta 4A) and dehydroepiandrosterone (DHEA) responses were significantly elevated. There were no differences in the responses of PCO and PCO-like patients. Although basal DHEA levels correlated with DHEA responses of CRF, basal levels of DHEA sulfate (S) could not be used to predict CRF responses. These data further confirm that there is heightened adrenal androgen activity in PCO whether the patients are 'classic' or PCO-like. Serum DHEA-S does not appear to be a good marker for this adrenal hyperactivity and might in turn also be under the control of other factors.