Indonesia’s Muslim preachers carry out their mission in a regulatory environment that is liberal when compared with the demanding regulations negotiated by preachers in Brunei and Malaysia. In recent times, however, the Indonesian government has given signs that it might favour a stricter regime of supervision and control. The authors – all of them social scientists with experience in studying Islamic communication in Indonesia – evaluate the pros and cons of such a move. Throughout this working paper, the authors approach preaching as a variety of public communication, but do not assume that preaching messages should faithfully replicate national norms of ethical citizenship. After all, preaching is communication oriented to Indonesians in a specific context, namely the context created in their routines of Islamic worship and learning. The authors provide an overview of social and political contexts for Islamic preaching, and examine the norms and rules that currently constrain preaching, referring both to Islamic norms as well as Indonesia’s positive law. The paper’s recommendations confirm the appropriateness of the low level of regulation traditionally applied to Islamic preachers, and encourage the government to be more sensitive to the ways in which the policies of Indonesian governments provide models for preachers about how the nation’s diversity should be treated in public communication.