Larry Poston explores the reality of da'wah - Islamic evangelism, or the `call' to Islam - as it has been interpreted and practised by Muslims in the West. Beginning with a brief examination of the expansion of Islam during its early centuries, Poston looks at the concept of da'wah as understood by the earliest followers of Muhammad. He shows how this early paradigm has been adapted to the demands of the Western context, and goes on to discuss the institutionalization of the new missionary strategy in North America.