This study compares the clinical, biochemical and laparoscopic findings in androgenized patients with (n = 33) and without (n = 17) polycystic ovaries (PCO). It included selective ovarian-adrenal vein catheterisation with measurement of testosterone, dihydrotestosterone, delta 4-androstendione, dehydroepiandrosterone and its sulfate, 17 alpha-hydroxyprogesterone and cortisol in peripheral and glandular venous samples; determination of free testosterone, oestradiol, oestron, LH, FSH and prolactin in peripheral blood; GnRH and TRH double stimulation, as well as dexamethasone suppression tests. There was no correlation between the morphological, clinical, and endocrine changes. A PCO-specific hormonal pattern was not identifiable. Based on catheterisation data, combined ovarian-adrenal androgen hypersecretion was found in 46% of PCO cases; purely ovarian (21%) or adrenal (12%) overproduction were not as frequent. The dynamic function tests proved to be non-specific; e.g., dexamethasone suppressed not only adrenal, but also ovarian androgen output. It is concluded from these data that PCO are not a nosologic entity, but rather a non-obligatory sign of hyperandrogenism. Laparoscopy is, therefore, without clinical relevance in these patients with non-neoplastic hyperandrogenaemia.