Human behavioral phenotypes are the result of complex interactions between genotype and the environment. Still, much remains unknown about the gene X environmental basis to adolescent delinquent involvement. Using data from the National Longitudinal Study of Adolescent Health, we examine whether a polymorphism in the dopamine D2 receptor (DRD2) gene interacts with religiosity to predict variation in adolescent delinquent involvement. The results of the analyses revealed a gene X environment interaction between the A-1 allele of DRD2 and religiosity in the prediction of adolescent delinquency. Limitations are noted, and the implications of the findings are discussed.