This book of Raja Yoga by Swami Vivekananda presents his understanding and interpretation of Patanjali's Yoga Sutras. Raja Yoga encompasses teachings from all the different paths, and it is from Raja yoga that hatha yoga and modern asana practices developed. Raja Yoga is constructed by its various elements, namely, Yama, Niyama, Asana, Pranayama, Pratyahara, Dharana, Dhyana, and Samadhi. In these, Yama refers to non-injury, truthfulness, non-covetousness, chastity, not receiving anything from the other. Niyama refers to the regular habits or observances; Asana refers to correcting the posture and explains yoga poses, and Pranayam means mastering and enlivening the life force; Pratyahara refers to inner reflection. Dharana is focused attention, Dhyana is meditation and Samadhi refers to freedom, liberation and enlightenment. The book is a powerful source of enlightenment for all that seeks liberation of the body and the mind harnessing peace in today's chaotic world.