To evaluate the influence of somatostatin analogue (octreotide) in the function of hypothalamic-pituitary-adrenal (HPA) axis in women with polycystic ovary syndrome (PCOS).Women referred to the Department of Obstetrics and Gynecology, Università Cattolica del Sacro Cuore.Twelve PCOS women and 12 normo-ovulatory controls.In early follicular phase, 1 μg/kg human corticotrophin-releasing hormone (CRH) was injected at 9: 00 a.m. and blood samples were collected for 90 minutes after stimulus; ACTH and cortisol plasma levels were measured. The following day at 8: 00 a.m., PCOS patients received an ACTH test (250 μg IV) and samples were collected 60 minutes after injection. After 6 weeks of octreotide treatment (100 mg SC twice daily), PCOS patients repeated the same study.Plasma cortisol and ACTH concentrations.The ACTH and cortisol baseline levels were similar in PCOS and control patients. The responses to human CRH of ACTH (incremental area = 437.86 ± 188.7 versus 175.78 ± 87.6 pmol/L; mean ± SD) and cortisol (incremental area = 17,293.6 ± 4,320.3 versus 5,885 (912.1 nmol/L) were significantly greater in PCOS with respect to control subjects. After octreotide treatment, ACTH response significantly decreased and no difference was observed with respect to controls (incremental area = 176.94 ± 91.4). Cortisol responses were decreased by treatment. However, they remained significantly higher than in controls. Treatment did not modify adrenal response to IV ACTH.Data suggest that, in the HPA axis, hyperfunction of PCOS somatostatin could be involved partially.