The significance of peers during adolescence is well established in the social science literature. However, relatively few studies have devoted attention to susceptibility to peer influence with regard to both its causes and consequences. The current study aims to add to this literature in two ways. First, it investigates the role of self-control in the etiology of susceptibility to peer influence. Second, it examines the independent and interactive effects of these two constructs on self-reported delinquency. Results indicate that individuals who are higher in self-control are less likely to be susceptible to peer influence, that susceptibility is a stronger predictor of delinquency than self-control, and that the influence of susceptibility on delinquency is moderated by one's level of self-control. In particular, the effect of susceptibility to peer influence on delinquency is stronger for individuals with higher levels of self-control. The implications of the findings for theory and future research are discussed.