BACKGROUND AND OBJECTIVES: Hypertension, especially in elderly is a strong risk factor for cardiovascular mortality and morbidity. Oxidative stress has been implicated as one of the underlying cause of hypertension. Yoga has been found to control hypertension in the elderly, but the underlying benefits of mechanism in relation to oxidative stress regulation remains unclear. The purpose of the study was to investigate the effect of yoga on oxidative stress in elderly with Grade-I hypertension. METHODS: An open parallel-arm randomised controlled study was conducted at BLDE University's Shri B.M.Patil Medical College, Hospital and Research Centre, India on elderly male individuals with Grade-I hypertension (n=57, age 60-80 years). Study (Yoga) group was assigned for yoga intervention and control group for walking for one hour in the morning for six days in a week for three months under the supervision of yoga instructor and physical training instructor respectively. Serum malondialdehyde (MDA) as an indicator of oxidative stress and antioxidants such as serum superoxide dismutase (SOD), reduced glutathione (GSH) and vitamin C levels were estimated. RESULTS: Yoga practice for three months has significantly reduced serum MDA level (p<0.001), and enhanced antioxidants level such as SOD activity (p=0.007), serum GSH (p=0.002) and vitamin C (p=0.002). In the control group, we observed a significant increase in serum MDA level (p=0.04) and reduction in serum vitamin C level (p=0.015) with no significant difference in the SOD activity and GSH level. CONCLUSION: These findings suggest that yoga is an effective means to reduce oxidative stress and to improve antioxidant defense in elderly hypertensive individuals.