Background and Objectives: In recent years, medical fraternity is attracted towards yoga. Modern man has become a victim of daily stress and stress related disorders. The stress related disorders affects cardiac and respiratory functions. The term Pranayama comes from prana- vital energy particularly the breath and ayama- to lengthen or extend. Presently yoga and Pranayama has revolutionized along with allopathic medicine in the treatment of bronchial asthma and other chronic disorders. The yogic procedure has proved to extremely useful in preventing full development of complications. The yogic technique which is followed in this study is known to have a beneficial effect in different stress related disorders. The present study tested the efficacy of regular practice of __ampersandsignlsquo;Pranayama__ampersandsignrsquo; in improving the respiratory functions. The present study was taken up as there are very few studies on the effect of yoga on specific pulmonary functions. Objectives: To assess the effect of Pranayama on various parameters of respiratory functions efficiency after six weeks of 30 min, daily yoga. Methods: A total of 35 undergraduate medical students of both the genders were taken in the study. The pulmonary function tests were assessed before the yoga training and were repeated after a period of six months of training. Pranayama practicing subjects were asked to take maximal sustained inspiration lasting for five seconds, followed by maximum sustained expiration which also lasted for five seconds during each practice. Results: Statistical analysis revealed significant improvement in the yoga group after six weeks of yoga training in few parameters of pulmonary functions (P__ampersandsignlt;0.001). Conclusion: The findings of the present study show that regular practice of yoga for six weeks increased parasympathetic tone, decreased sympathetic activity and improved respiratory functions. The students opting for stressful professional courses can adopt yoga training in their routine life so as to combat the stress.