A little over three decades ago, during the reign of the last Pahlavi monarch Mohammad Reza Shah Pahlavi, non-Muslim religious minorities in Iran experienced life within a relatively tolerant society. Since the Islamic Revolution in 1979, Iran’s native Zoroastrians, Jews, Christians, Mandaeans, and Baha’is have experienced increasing discrimination, isolation, and intimidation. Those non-Muslim religious minorities provide Iranian society with confessional pluralism and cultural diversity, thereby serving also as a moderating population sliver against Shi‘ite fundamentalism. But now the non-Muslim communities collectively have diminished to less than 2 percent of Iran’s 75,2 million residents. Yet, these minorities have attracted very limited domestic and international attention or concern because their situation is poorly understood. This article, based on extensive fieldwork in Iran during the 1980s, 1990s, and 2000s, examines the situations of those Zoroastrians, Christians, Jews, Mandaeans, and Baha’is. While Sunnis also are a religious minority in Iran and do experience prejudices too, intra-Muslim tension with its origins in seventh century religious disputes and its geopolitical reverberations to the present day go beyond the scope of this article.