Muslims in Austria have, since 1982/83, had the unique privilege of providing Islamic religious education in secular public schools, including primary, middle and secondary schools. As well as opportunities, this privilege brings responsibilities and challenges to the Muslim community. Since its beginnings, Islamic religious education in Austria has, among other things, been especially characterized by the heterogeneity and diversity of its participants, as well as the general diversity in society and the secular context of public schools. In this context, theoretical discussions about the orientation of and justification for Islamic religious education in secular public schools suggest that for both teachers and the subject itself, an awareness, appreciation and inclusion of diversity, dialogue, multi-perspectivity and reflexivity is required. The empirical study on the professionalization of Islamic religious education, drawn on in this article, is based on Muslim teachers’ own perspectives and experiences. The research findings of that study show how Muslims become Islamic religious education teachers, how Muslim teachers see their roles in secular public schools, how they teach and approach Islam or Islamic topics, what the challenges of teaching Islamic education in public schools are, and other related topics. This article (re-)analyzes used and unused data from the study and focuses on how diversity and controversial topics can be approached in the context of Islamic religious education.