Inspired mainly by Barth's and Jacobson's models of analysis, the authors explore the interrelationship between religion and ethnicity among young Iranian women who are Christian Armenians, Sunni Kurds and Shi'ite Azerian Turks. The major question is whether modern Iran displays a unitary notion of Islam, in which Muslims are considered as a single community and people are categorized in terms of their religious identity, as if there was no place for other identities. Alternatively, the authors ask whether modern Iran presents religious and ethnic communities and identities in all their diversity. Their findings reveal a variety of conclusions. First, Iran exhibits a diversity of identities and differences among both Muslim and non-Muslim people, all of whom live under the rule of an Islamic government. Second, both the religious and ethnic boundaries of young Iranian women are relatively permeable and fluid in comparison with those of previous generations. Third, the state's ideological boundaries have not persuaded young Muslims to show solidarity towards fraternity based on the "ummah" or Muslim community.