There are over one and a half billion Muslims in the world today, but a schism occurring in early Islamic history divided the house of Islam into two factions: the Sunnis, comprising roughly ninety percent of adherents today, and Shi’ites, comprising approximately the remaining tenth. Sunnis and Shi’ites have long engaged in debates with and polemic against each other, producing a substantial body of literature. This presentation will explore the continuation and evolution of sectarian debate in cyberspace. The reader is introduced to both the themes characterizing this discourse and polemical techniques, including those favored or facilitated by the medium of the web. The thesis concentrates on Shi’ite material, leaving Sunni internet activity for future investigation. Treatment of the very large number of constantly shifting and proliferating sectarian websites is enabled by the fact that they exhibit common themes and patterns, facilitated by the constant interchange, copying and linking that are characteristic of the web. The research is limited to sites posted in English, which has become a lingua franca of the web, including Muslim religious sites. The thesis also assesses the effects of the internet on sectarian debate and relations. The chief effect has been to provide an outlet for popular, “lay” voices; within the last few decades, the internet has given people of all walks of life a forum in which to share their views and convictions, and Sunni-Shi’ite dialogue is no different. The impact overall, however, has been negative, since the internet has served largely to intensify or escalate the negative features of polemic by creating a new, trans-national space in which anonymous authors can, without much learning or restraint, attack a depersonalized “other” while surfers instantly access that material and pass it on. Because of the Shi’ite minority position, some Shi’ite sites appear to be somewhat more temperate and begin by attempting to present a picture of their tradition acceptable to Sunnis (Chapter One); but this strategy soon leads to more overt critique of Sunnism and is finally undermined by material and tactics that are, like those found in Sunni sites, openly hostile (Chapter Two). Surprisingly given the accessibility of the web, there are no significant sites or internet voices (at least in English) that encourage real dialogue and respect, a disappointing reality especially in view of the current rise of sectarian conflict and violence in the Muslim world.