Background: Psychological stress, in this era of urbanization, has become a part and parcel of our lives and has lead to serious problem affecting different life situation and carries a wide range of health related disorders. Aims & Objective: To observe the effects of Pranayama on GSR. Pulse rate and blood pressure. Material & Method: This was an open labeled, prospective, uncontrolled, single centered, single arm, comparative, clinical intervention study conducted in the Department of Pharmacology, Grant Govt. Medical College, Mumbai, over a period of two months period August-September 2009 on 15 Prehypertensive subjects. Results: A total of 15 subjects who were Borderline hypertensive / Pre-Hypertensive, according to the JNC VII Classification, were enrolled in the study. Of which 10 were male and 5 were females, all in the age group of 22-35 yrs with a BMI of 19.63 – 30.11 with an average of 24.80. No significant change was seen when baseline GSR reading was compared with 15th day reading, but on 30th day significant change observed. When the baseline value of pulse was compared with that of the 15th and 30th day, a good positive change was seen in resting pulse. Similarly, BP recording also showed a good positive effect when baseline value was compared with that 15th and 30th day. Conclusion: The study concludes that practicing Pranayama on a regular basis increases the parasympathetic tone and blunts the sympathetic tone of the body. This has shown good beneficial effects on the Pulse, BP and GSR.