Background: Diabetes mellitus is the most common metabolic disorder worldwide. We aimed to determine the metabolic and clinical responses to Bunium Persicum (Black Caraway) supplementation in overweight and obese patients with T2DM. Methods: Participant recruitment took place in the diabetic clinic of Bu-Ali hospital in Zahedan. Due to the eligibility criteria, 60 participants were randomly placed into two groups, namely placebo (n = 30) and BP (n = 30). The supplementation was considered one 1000 mg capsule 2 times /day BP by meals (lunch and dinner) for 8 weeks. Physical activity levels, dietary intakes, anthropometric measurements [weight, height, and waist circumference], glycemic indices [fasting blood glucose (FBG) and insulin (FBI)], blood lipids [triglyceride (TG), total cholesterol (TC), high-density lipoprotein cholesterol (HDL-c), and low-density lipoprotein cholesterol (LDL-c)], and serum nesfatin-1 level were determined. Homeostasis model assessment-insulin resistance (HOMA-IR), Quantitative insulin sensitivity checks index (QUICKI), and Body Mass Index (BMI) were computed. Results: In comparison with placebo, BP significantly decreased FBG, HOMA-IR, and BMI (P < 0.05). The differences in the FBI, QUICKI, TG, TC, LDL, HDL, WC, and Nesfatin-1 were not significant (P > 0.05). Conclusion: BP supplementation improved serum glucose indices and BMI among overweight and obese T2DM patients. Further trials are needed to confirm results.