This book describes the history of yoga, its significance, its place in today's society, and Professor Rai's research in this field. Professor U.C. Rai is a distinguished physiologist in New Delhi. He has devoted thirty years of his life to teaching medicine. He has been Professor and Head of the Department of Physiology in New Delhi and Pondicherry. He was President of the Association of Physiologists and Pharmacologists of India in New Delhi. He is a member of the World Health Organisation (WHO). In addition, he has lectured at Oxford University, Leeds University and the Brain Research Institute in Zurich. For the past eight years, he has been working on the medical effects of a new form of yoga founded by Shri Mataji Nirmala Devi: Sahaja Yoga. Under his supervision at the University of New Delhi, three doctors have obtained their doctorates in medicine based on research into Sahaja Yoga. Scientific papers on his work have been presented at several international conferences. Prof Rai has conducted his research on patients suffering from epilepsy, high blood pressure, asthma, migraines and heart disease, and has also worked on stress. The results are very encouraging and suggest that Sahaja Yoga has an overall beneficial effect on health. Sahaja Yoga, as an inexpensive, accessible complementary method, is a very interesting prospect because it contributes to the health strategy for all as defined by the WHO for the year 2000; this definition combines the physical, mental and social aspects of human beings, which are an integral part of the philosophy of yoga.