Satyarth Prakash' (Light of Truth) is the Magnum opus of Swami Dayanand Saraswati, the living embodiment of Vedic life and thought and the illustrious son of India who founded the Arya Samaj movement. It occupies a prominent place in the Classical, Religious and Philosophical literature of the world. Its main objective is to depict the true face of Hinduism and to set an agenda for reformation of world religions in the larger of interest of humanity. The present English translation is conspicuous for its richness of thought and plucking out the actual and factual intention of the original author in the most modern English terms. This edition is beneficial to both learned and laity, as it brings home the main theme in a very simple and lucid language and all technical aspects dealing with grammar and etymology have been cited under footnotes to serve the purpose of reference to the scholars.