INTRODUCTION: One of the complications associated with diabetes mellitus is decrease in bone mineral density (BMD). Therefore, quantification of BMD for these patients before a dental implant procedure is essential. Cone beam computed tomography (CBCT) is an important tool that can be used for qualitative and quantitative bone assessment for treatment planning of dental implants. OBJECTIVES: Evaluation of mandibular bone mineral density measured by CBCT and its correlation to T-score obtained by dual energy xray absorptiometry (DEXA) in relation to blood glycemic control as detected by glycosylated hemoglobin (HbA1c) in type 2 diabetic patients (T2DM). MATERIALS AND METHODS: The study was conducted clinically on twenty-four patients having T2DM, referred for CBCT examination as a part of implant planning. BMD was measured for each edentulous mandibular space using CBCT scan. The patients were grouped according to the level of HbA1c into 4 groups; control group, well-controlled group, moderately controlled group and poorly controlled group. Additionally, each candidate was examined radio-graphically using DEXA. Then, a statistical correlation between HbA1c values in relation to mandibular BMD values and T-score values was investigated. RESULTS: there was a statistically significant correlation between HbA1c values and BMD variables including: mandibular edentulous quad BMD and T-score values (p <0.001), and a statistically significant correlation between T-score value and Mandibular edentulous quad BMD (p <0.001). CONCLUSIONS: Osteoporosis is a commonly underestimated problem in diabetes patients. Osteoporosis can be predicted using CBCT, so it's the dentist responsibility to refer osteoporotic patients once being suspected.