This article examines rehabilitation programs for Islamist militants in light of the literature on rehabilitative interventions for ‘‘ordinary’’ criminal offenders. The article describes the more salient characteristics of Islamist deradicalization and disengagement programs; namely that a focus on ideology and religion has so far been the most promoted aspect of programs, and a great deal of effort has been put into enlisting credible sources of information and developing convincing arguments. It also commends the fact that these programs do appear to some extent to utilize the potential for groups of individuals to support each other’s individual rehabilitation. However, it ultimately reaffirms that the biggest challenges at present are still risk assessment, and definitions and measurement of success. In the face of uncertainty on these issues, the content of criminal and terrorist rehabilitation programs will always differ but criminology can help to clarify issues, improve practice, and develop realistic expectations for rehabilitation of Islamist terrorists.