Periodontal disease, a chronic adult condition is characterized by the destruction of connective tissue and bone. As a result of stimulation by bacterial antigen PMN produces free radicals via respiratory burst as a part of host response to infection. Patients with periodontal disease display increased PMN number and activity. This proliferation results in high degree of free radical release culminating in heightened oxidative damage to Periodontium. Damage mediated by free radicals can be mitigated by "ANTIOXIDANT DEFENSE SYSTEM ". Physiological alteration and pathological states produced by free radicals depend on disequilibrium between free radical production and antioxidant levels leading to oxidative stress. Diabetes Mellitus, is a group of complex multisystem metabolic disorders. Hyperglycemia is a hallmark of diabetes mellitus as are its chronic metabolic complications4. Hyperglycemia induces oxidative stress. The present work was carried out to investigate the total antioxidant capacity in saliva of type 2 diabetes mellitus patients and healthy subjects with and without periodontal disease. After clinical measurement and samplings, total antioxidant capacity in sali