This study investigated the social dynamics that underlie the negative association between religiosity and cigarette use among U.S. adolescents. Using data from the 2007 National Survey on Drug Use and Health, the authors used a theory-based conceptual model (vicarious learning networks [VLN]) to examine the role that key reference group norms play in the religiosity--smoking relationship. This relationship is partially mediated by parents' and close friends' perceived disapproval for smoking. However, religiosity maintains a strong negative association with smoking. Consistent with the VLN model, cigarette use varied substantively based on reference group normative configurations. To the extent that the protective effects of religiosity arise from its influence in structuring the social milieu, some of religiosity's benefits could potentially be leveraged through interventions that promote healthy norms among reference groups within the social network. The VLN model may be a useful tool for conceptualizing the transmission of health behavior through social learning processes. (Contains 4 tables.)