Background: The percentage of obese postmenopausal women with metabolic syndrome is rising, and physical factors associated with the metabolic syndrome prevalence or incidence are also rising, including high body mass index (BMI), visceral fat area (VFA), low plasma sex hormone-binding globulin (SHBG) levels, and low cardiorespiratory fitness. Therefore, we investigated the influence of aerobic exercise on SHBG, body fat index (BFI), and metabolic syndrome factors in obese postmenopausal Korean women. Methods: Thirty healthy postmenopausal, women aged 53.46 +/- 2.4 years and with over 32% body fat, were randomly assigned to an aerobic exercise group (EX; n = 15) or to a "nonexercise'' control (Con; n = 15) group. The primary outcome measurements were serum SHBG, lipid profiles, insulin levels, and metabolic syndrome factors. Secondary outcome measurements were body composition, VFA, blood pressure (BP), and homeostasis model assessment of insulin resistance (HOMA-IR). Results: Posttraining body weight and BFI (P < 0.05), total cholesterol, glucose, and insulin levels (P < 0.01), BP, and HOMA-IR (P < 0.001) decreased, whereas SHBG (P < 0.001) and metabolic syndrome factors (P < 0.01) improved in the exercise group but not in the control group. SHBG levels also showed a significant positive correlation with high-density lipoprotein cholesterol (HDL-C) and significant negative correlations with glucose, diastolic blood pressure, fat mass, BMI, and percent body fat (P < 0.05). Conclusions: Our findings indicate that aerobic exercise improves body composition, SHBG, insulin levels, and metabolic syndrome factors. These findings suggest that in obesepostmenopausal Korean women, 16 weeks of aerobic exercise is effective for preventing the metabolic syndrome caused by obesity.