BACKGROUND: A complex two-way relationship exists between periodontitis and diabetes mellitus (DM). Diabetes mellitus is often preceded by low‑grade inflammatory response. AIM: To evaluate the effect of non surgical periodontal therapy on clinical response and glycemic control in diabetic patients with periodontitis. MATERIALS AND METHODS: A prospective interventional comparative clinico - biochemical study was planned in 60 subjects with type 2 DM having moderate generalized chronic periodontitis. Clinical diagnosis of moderate generalized chronic periodontitis was made on the basis of probing pocket depth ≤ 5mm and clinical attachment loss of 3-4 mm in a minimum of 6 teeth. Clinical parameters recorded were plaque index, gingival index, bleeding on probing, probing pocket depth and clinical attachment level at sites of selected teeth. Subsequently, the clinical and biochemical parameters were recorded at baseline and 6 months post therapy.