Abstract-Diabetes has become the fastest growing chronic disease in the world. Therefore, in order to manage it, behavioral changes in lifestyle including physical activity, dietary, monitoring of blood glucose levels (BGL), and obedience to treatment are needed. A good self care (self-management) of patients with diabetes will help them manage the disease. American Association of Diabetes (ADA) suggest people with diabetes type 2 to have selfcare behaviors that can improve their quality of life while reducing the complications associated with the disease (Bonner et al., 2016). The aim of the research was to analyze the correlation between self care behaviors and HbA1c levels of the patients with type 2 diabetes in Binjai, North Sumatra Province. The design of the research was descriptive analytic with cross sectional approach. The population in this study was all patients with type 2 diabetes mellitus in eight community health centers in Binjai. The samples were consecutive sampling of 118 people who meet the criteria. Data gathered were analyzed using Pearson Correlation. The result of this study suggested that the majority of samples (102 people or 86.4%) with type 2 diabetes mellitus in Binjai has low attention to do self care behavior. The average HbA1c level of the diabetic patients was 9.8% (uncontrolled). Meanwhile, the result of the Pearson Correlation Test showed a correlation between self care behaviors and HbA1c level in diabetes patients in Binjai (p <0.05). The better the self-care behavior of the diabetes patients the lower the HbA1C levels is. Self-care behavior is the determinant factor of the controllable diabetes. To improve self-care behavior, cooperation between doctors and health workers to provide continuing education is essential in order to increase understanding and independence of the patients with type 2 diabetes.