Background: Yoga is probably best lifestyle ever devised in the history of mankind. The word YOGA comes from the Sanskrit root ?YUJ? which means to unite. (the union of body with the soul.) Kriya in Sanskrit means action, most commonly refers to technique or practice with in a yoga practice. Sudarshana kriya is a unique rhythmical breathing process to eliminate stress and support the various organ systems with in the body, transform overpowering emotions and restore peace of mind. Objective: To assess the effects of Sudarshana kriya on respiratory function. Materials and methods: 36 subjects practicing Sudarshana kriya for more than 2 years, who were in the age group of 18-30 years nonsmokers (interviewed using standard questionnaire), from Art of living ashram, Bengaluru were chosen as test group. 36 subjects who were not practicing any type of yoga of same age group and non smokers were chosen as controls. Pulmonary function tests like FVC, FEV1, FEV1/FVC and PEFR results were analysed using appropriate statistical method. Results: Study group showed significantly higher FVC, FEV1, FEV1/FVC. Suggesting sympathovagal balance. Conclusion: Pulmonary functions improve significantly with Sudarshana kriya due to respiratory muscle strengthening and good lung expansion and by harmonizing the central nervous system and our breathing.