To practicing bonpos, Bön simply means the true religion of Tibet, while to Tibetan Buddhist, Bön refers to the false teachings and practices that were prevalent before Buddhism finally succeeded in gaining a firm hold on the county. The present study resulted from a period during which the author, a renowned scholar of Asian languages and cultures, was engaged in intense contact with practicing bonpos. It consists of the translation of fundamental texts of Bön, based on a manuscript of over 500 years of age, in which the entire Bön tantric teachings and rituals are summarized. In many ways remarkably parallel to the early Buddhist teachings, much of the Bön tradition was subsequently incorporated back into Buddhism when that religion was formally adopted into Tibetan culture. With a new foreword by Samten G. Karmay, this important study, first published in 1960s and long out of print, will be welcomed by all with interest in the religions of the Himalayas.