The relationship between religiosity and crime has been the subject of much empirical debate and testing over the past 40 years. Some investigators have argued that observed relationships between religion and crime may be spurious because of self-control, arousal, or social control factors. The present study offers the first investigation of religiosity, self-control, and deviant behavior in the prison context. We use survey data from a sample of 208 recently paroled male inmates to test the impact of religiosity and self-control on prison deviance. The results indicate that two of the three measures of religiosity may be spurious predictors of prison deviance after accounting for self-control. Participation in religious services is the only measure of religiosity to significantly reduce the incidence of prison deviance when controlling for demographic factors, criminal history, and self-control. We conclude with implications for future studies of religiosity, self-control, and deviance in the prison context. © 2011 SAGE Publications.