Objective: Uteroglobin (UG), also known as secretoglobin family 1A member 1 (SCGB1A1), is a steroid-inducible immunomodulatory protein found only in mammals. Although numerous studies demonstrated that UG is a multifunctional protein with anti-inflammatory properties, its physiological functions are not yet fully understood in humans. Because one of the pathophysiology of type 2 diabetic mellitus (T2DM) is chronic inflammation, UG levels may be different in subjects with normal glucose tolerance and patients with T2DM. Therefore, the aim of the present study was to investigate the relationship of serum UG levels and several metabolic parameters in patients with newly diagnosed T2DM. Methods: A total of 80 participants with newly diagnosed T2DM and 80 controls without T2DM were studies. Diabetes was diagnosed according to the American Diabetes Association criteria. We measured blood chemistry, lipid profiles, fasting and post-load 2-h levels of glucose, insulin, and c-peptide. Serum UG levels was measured in fasting blood. Results: Body mass index (BMI); fasting levels of glucose, insulin, and c-peptide; post-load 2-h levels of glucose and insulin; HbA1c levels (%); scores on the homeostasis model assessment of insulin resistance (HOMA-IR); and estimated glomerular filtration rate (eGFR) were significantly higher in T2DM than control subjects. Interestingly, the serum concentration of UG was significantly lower in T2DM than control subjects. Conclusion: These preliminary results suggest and a possible role for circulating UG in patients with T2DM, although further evaluation for mechanism is required.