The Pentecostal and charismatic movements showed astonishing growth in the twentieth century so as to arrive at a total that is said to include at least 400 million people worldwide. The academic study of the Pentecostal and charismatic movement has been gaining momentum in the last few years, both as an element within contemporary religious studies and as a strand within the subject area of church history, going back to the early church. This student-friendly text is essential reading for students of Theology and Religious Studies, taking second or third year modules in Pentecostal studies. It is also of great relevance to students of sociology of religion, as well as cultural and historical studies of religion and religious movements. In addition to a comprehensive and accessible introduction to the subject, it offers useful resources such as suggestions for further reading, questions for reflection and a glossary of technical terms. Dr William K Kay is Reader in Practical Theology and Director of the Centre for Pentecostal and Charismatic studies at the University of Wales, Bangor.