The association between delinquent peers and delinquent behavior is among the most consistent findings in the criminological literature, and several recent studies have raised the standards for determining the nature and extent of peer influence. Despite these advances, however, key questions about how deviant behavior is socially transmitted remain unresolved. In particular, much of the research examining peer influence has been limited to peer behavior, despite a rich literature supporting the salience of beliefs, such as expectations and moral approval, in shaping behaviors. In the current study, I model the peer influence and selection processes with longitudinal social network analysis to reexamine the contributions of peer beliefs and behaviors to adolescent drinking. I find evidence that beliefs related to peer drinking have both a direct and an indirect impact on behavior and play an important role in the friendship selection process. These results highlight the importance of understanding how peers influence deviant behavior and suggest that peer beliefs are an important part of this relationship.