Synopsis Demons worship is a form of belief which has its independent origin from the orthodox form of religions. This cult is amorphous and ill-organized, possessing little or no sacred literature and no established priesthood. Later, it has been, in many cases, annexed and absorbed by almost all religions of the world. This volume is an in-depth study of demonic belief and practices of nineteen important religious communities of the world and its impact on their socio-cultural life from the beginning of civilization to contemporary world. This study is classified into two parts- Oriental demonology and Occidental demonology. First part deals with demonic belief and practices in twelve Oriental religious communities, and the second part describes seven Occidental religious practices of demonic belief.