Background: Diabetes is a metabolic disease that various factors are involved in its occurrence. This study aims to investigate the relationship between leptin level and HbA1c with physiological characteristics. Methods: In this study, 236 blood samples were taken from type 2 diabetes patients based on the inclusion and exclusion criteria. Then the level of leptin, HbA1c and other clinical characteristics were evaluated. Results: The results of this study showed that there is a positive correlation between leptin, HbA1c, WHR, BMI and abdominal circumference. Therefore, the increase of each of these parameters affects the other. Conclusion: The results of this study and their comparison with other similar studies in this field, it can be concluded that leptin, Body mass index (BMI), and Waist-to-hip ratio (WHR) are related to diabetes and have a positive correlation with each other and Haemoglobin A1c (HbA1c). Therefore, by controlling each of them, the probability of another occurrence is reduced and this can be included in preventive programs.