This book addresses the role of extensive reading on vocabulary retention. Much has been written, on both theoretical and empirical levels, about the idea of extensive reading and the suggestion that some kind of extensive reading activities need to be incorporated into second language (L2) communicative contexts. However, this book will first elaborate on the need to utilize extensive readings in our pedagogy and L2 teachings. Pedagogical possibilities and strategies will then be suggested, and examples provided of tasks that may help to realize this goal in classroom contexts. Relevant empirical evidence on the effectiveness of such tasks will be presented and discussed. The major goal is to explore the effect of an extensive reading program on learners' vocabulary knowledge. This book was conducted to help educators find different ways for developing their learners’ vocabulary size and knowledge, and seeks more systematic and effective ways of learning incidental vocabulary through extensive reading.