In this article the author studies the beginnings, believes and principal arguments of Religious terrorism and questions them based on analytical assessment traditions. It evaluates the legitimacy of the concept and its effects for research and policy practices. It argues that the distinctions typically drawn between nonspiritual and religious terrorism are problematic, both theoretically and empirically, and that in its usual assumptions, the term is misleading about the intentions, foundations and behavior of groups classified as ‘religious terrorist’. In particular, it shows that the diversity of those labelled “religious terrorists” is so mixed, and often so indistinguishable from their ‘nonspiritual’ equals, that the term has little meaning without further limitation, while simultaneously darkening key characteristics of both ‘religious’ and ‘nonspiritual’ violence. It then goes on to illustrate how the term, rooted in a particular historically situated understanding of religion and a particular set of power structures, serves as a disciplinary device to domesticate ‘political religion’, delegitimizing certain actors while legitimizing a number of highly contentious counterterrorist practices designed to deal with those described as ‘religious terrorists’. The article ends with some suggestions for alternative ways to study the role of beliefs and institutional structures, religious or otherwise, in producing political violence.