In the context of the vivid activity of Muslim individuals and groups on the Internet and the recent technological developments in the field of computer mediated communication, podcasts offering a wide range of religious information and/or advice to Muslim (and non-Muslim) listeners play an increasingly important role. Being an integral part of the Web 2.0's online landscape and presenting, at the same time, many characteristics of more “traditional” audio media such as cassette recordings, podcasts cannot only be located at the intersection between virtual space and “real world”, but represent, as a medium, also a direct continuation of older forms of Muslim media usage for da'wa-purposes and propagandistic aims. This article attempts to analyze in how far the use of podcasts (and to a smaller extent of videocasts) by Muslim groups and individuals contributes to the emergence of a Muslim online “counter public” sometimes challenging, sometimes reinforcing existing authority structures. Special attention is paid to the question which means and features specific to this new medium Muslim podcasters use to legitimize their religious authority, and to the question in how far established symbol systems commonly relied upon in the Muslim community are used as instruments for the construction of religious online authority and the redistribution of Definitionsmacht. Furthermore, it discusses to what extent questions of “right belief” and “correct religious practice” play a role in these processes. For this purpose, style and content of four selected podcasts (Zaytuna Institute Knowledge Resource Podcast, MeccaOne Media Podcast, Ahmadiyya Podcast, Alt.muslim Review) are analyzed in order to illustrate different ways in which this new medium is used by Muslim groups today. It is shown that podcasts—as part of the overall media spectrum—are used by Muslim groups for internal and external da'wa-purposes, as well as for the reinforcement of existing power and authority structures (e.g. by projecting the presence of the group's leader both into time and into space) and as a means to cope with institutional and communal crisis. They might also become an important instrument not for the (re-)construction, but for the deconstruction of religious authority.