This study was performed to evaluate the impact of insulin sensitivity on sex hormone-binding globulin (SHBG) and sex steroids in premenopausal and postmenopausal euthyroid obese women. A total of 227 women were eligible for this study. All were euthyroid, obese, and overweight; ages ranged from 25 to 69 years. Women were divided into premenopausal (n=151) and postmenopausal (n=76) groups. SHBG, sex steroids, thyrotropin, fasting and postprandial glucose, lipid profile, uric acid, serum insulin, and blood pressure were measured. No significant difference was found in mean SHBG levels between premenopausal and postmenopausal women. The investigators observed that during transition from premenopause to postmenopause, SHBG levels increased in insulin-sensitive women in the postmenopausal group; however, SHBG levels decreased in insulinresistant women. It was concluded that SHBG blood concentration factors are likely to change during transition from premenopause to postmenopause. The positive effect of estradiol on SHBG levels is probably stronger in premenopausal women than in postmenopausal women. It has been noted that after menopause, the impact of insulin resistance on SHBG level seems more important than the effect of estradiol.