Diabetes mellitus (DM) requires patients to take on a high level of responsibility for their daily care. Thus, care for people with diabetes is moving toward patients taking an active role in their own health care. To evaluate the impact of self-management care on glycemic control in individuals with DM and determine the correlation between glycated hemoglobin (A1C) levels and self-management practices. A cross-sectional descriptive study was conducted among diabetes patients at a diabetic center in Armed Forces Military hospitals, Southern region. A questionnaire of demographic and clinical information and self-management measured with the Diabetes Self-Management Questionnaire was used. Glycemic control was assessed using HbA1c levels. The study involved 255 patients with diabetes, of which 61.2% were females and 81.6% aged ≥41 years. The average diabetic self-management score was 6.49 on a scale of 10. The mean glucose self-management subscale score was 7.83 points, while the mean dietary control (DC) subscale score was 4.89. The patients had a mean physical activity (PA) subscale score of 6.31 and 8.75 for healthcare usage. Patients with higher education were significantly less likely to have poor glycemic control. Diabetes duration was significantly and positively correlated with poorer glycemic control. Mean perceived PA and DC scores were significantly associated with glycemic control. Type 2 diabetes patients had satisfactory self-care practices. Many did not achieve the target glycemic control for diabetes.