Religiousness has consistently emerged in the literature as a protective factor for alcohol use. Relatively few studies have empirically explored possible mechanisms for this robust effect. The present study examines descriptive drinking norms as a potential mediator of the religiousness--alcohol consumption association. Consistent with the literature, religiousness was inversely related to alcohol use and alcohol-related problems. Religiousness was also inversely related to descriptive drinking norms for close friends but not for more distal targets. Descriptive drinking norms for one's close friends mediated the relationships between religiousness and alcohol use outcomes. These results suggest that religiousness may influence alcohol use outcomes through perceptions of close friends' alcohol use. Implications of these findings and recommendations for future directions are discussed in the context of developing theory-based interventions to address problems associated with alcohol use.