Evidence-based practice suggests that clinicians should integrate the best available research with clinical judgment and patient values. Treatment of religious patients with scrupulosity provides a paradigmatic example of such integration. The purpose of this study is to describe potential adaptations to make exposure and response prevention, the first-line treatment for obsessive–compulsive disorder, acceptable and consistent with the values of members of the Ultra-Orthodox Jewish community. We believe that understanding these challenges will enhance the clinician's ability to increase patient motivation and participation in therapy and thereby provide more effective treatment for these and other religious patients. © 2007 Wiley Periodicals, Inc. J Clin Psychol 63: 925–941, 2007.