Previous studies have demonstrated that brain-derived neurotrophic factor (BDNF) played a role in the eating behavior and glucose and lipid metabolism. In this study we measured the serum BDNF levels in newly diagnosed female patients with type 2 diabetes mellitus (n = 24, aged 34-59 years) and female subjects with normal glucose tolerance (n = 7, aged 34-56 years). The serum BDNF level was found to significantly increase in diabetic patients in comparison to that in healthy subjects (P < .05). In these patients, the serum BDNF level showed positive correlation with the body mass index (r = 0.535, P < .01), the percentage of body fat (r = 0.552, P < .01), the subcutaneous fat area based on computed tomography scan (r = 0.480, P < .05), the triglyceride level (r = 0.470, P < .05), the fasting blood glucose level (r = 0.437, P < .05), and the homeostasis model assessment of insulin resistance score (r = 0.506, P < .05), whereas it showed a negative correlation with age (r = -0.486, P < .05). The partial correlation coefficients adjusted by age showed significant differences regarding the body mass index (r = 0.423, P < .05), percentage of body fat (r = 0.504, P < .05), and triglyceride level (r = 0.426, P < .05). These results provide the first evidence that an increased BDNF is associated with a prevalence of type 2 diabetes mellitus. In addition, the BDNF is related to the total and abdominal subcutaneous fat mass and energy metabolism in the newly diagnosed female patients with type 2 diabetes mellitus.