Objective: To determine the impact of ovary-secreted products on adrenocortical function in women with PCOS by studying the adrenocortical response to acute adrenocorticotropic-stimulating hormone (ACTH) stimulation before and after bilateral oophorectomy. Design: Prospective study. Setting: Tertiary care medical center. Patient(s): Fourteen women with PCOS, scheduled for bilateral oophorectomy for benign indications, on postoperative transdermal estradiol (E2). Intervention(s): Physical examination, blood sampling before and after oophorectomy, measurement of hormone levels; assessment of basal (Steroid0), maximum stimulated (Steroid60), and net increment (ΔSteroid) levels of androstenedione (A4), dehydroepiandrosterone (DHEA), and cortisol (F) before and after ACTH 1-24 stimulation. Main Outcome Measure(s): Preoperative and postoperative basal and ACTH (1-24) stimulated hormone levels. Result(s): Total testosterone, free testosterone, and estrone levels decreased, and follicle-stimulating hormone levels statistically significantly increased after oophorectomy. No statistically significant differences in E2, DHEA sulfate (DHEAS), or sex hormone-binding globulin levels were detected. Basal and ACTH-stimulated A4 levels statistically significantly decreased after oophorectomy, and ΔA4 was statistically significantly increased. No statistically significant differences in DHEA0, DHEA60, or F0 levels were detected. The F60 and ΔF levels tended to increase after oophorectomy, but the differences did not reach statistical significance. Conclusion(s): Ovarian factors do not appear to contribute significantly to the adrenocortical dysfunction of PCOS.