Increased oxidative stress as a result of excessive production of lipid peroxidation and reactive nitrogen species in association with disturbances in antioxidant defense system have been implicated in the pathogenesis of several diseases, most notably oral cancer. Thus, estimation of oxidant antioxidant status in oral squamous cell carcinoma patients could serve as a useful marker in choosing the correct therapy and also to monitor the effectiveness of such therapy and tumor recurrence. Also antioxidant therapy might prove useful in preventing the adverse effects caused by chemotherapy and radiotherapy.As free radicals are considered to be involved in the development of pre-cancer, determination of oxidant-antioxidant status in these patients may be helpful in successful management, thereby arresting it in early stages and avoiding the possible consequences of progression to malignancy.