['To evaluate the effectiveness of sibutramine therapy alone and in combination with ethinyl estradiol-cyproterone acetate (EE-CPA) on the clinical and metabolic parameters of obese women with polycystic ovary syndrome (PCOS).', 'Prospective randomized, controlled study.', 'Endocrinology and gynecology clinics.', 'Forty obese women with PCOS.', 'Group 1 was treated with oral EE-CPA (35 microg-2 mg/day), group 2 with oral sibutramine (10 mg/day), and group 3 with a combination of EE-CPA plus sibutramine for 6 months. All groups were advised to consume a diet of 1200 kcal/day.', 'Measurements were performed before and 6 months after treatment of body mass index, waist-to-hip ratio, systolic and diastolic blood pressure, Ferriman-Gallwey hirsutism score, total testosterone, free testosterone, sex hormone-binding globulin, dihydroepiandrosterone sulfate (DHEAS), total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, triglyceride, glucose and insulin during oral glucose tolerance test, and insulin sensitivity index; area under the curve for glucose and insulin were obtained from OGTT.', 'Body mass index, Ferriman-Gallwey hirsutism score, serum total testosterone, free testosterone, and DHEAS levels were significantly decreased and SHBG was significantly increased in all groups at the end of the study. WHR, diastolic blood pressure, and serum triglyceride level were significantly reduced only in the sibutramine group.'] Does sibutramine have a positive effect on clinical and metabolic parameters in obese patients with polycystic ovary syndrome?