Islamic Minority Groups in Indonesia. Indonesia makes Pancasila the basis of the state, and the way of life of the nation and state. Although not being a religious state, the majority of the Indonesian population embraced Islam, especially Ahlussunnah Waljamaah (Sunni). Among the Sunni communities are affiliated with the organization Al Jam'iyatul Washliyah, Nahdlatul Ulama, Persis, and Muhammadiyah all of which represent in the Majelis Ulama Indonesia (MUI). Although dominated by Sunni Muslim majority, new mainstreams have also emerged as Shia and Ahmadiyah as perceived by the MUI as deviant sects. Frequently there are discursions and conflicts between Sunni and Muslim minorities. This article examines the existence of Muslim minorities in Indonesia, and the MUI's response to the various streams. Based on observations and document studies, there are significant influxes and understandings in Indonesia with a significant number of followers raising responses from MUI, including Islamic organizations, which in turn led to religious fatwas on the deviation of faith and perversion in Indonesia.