Violence and drug use are major health threats to society. If effective prevention programs are to be designed, origins of these behaviors and their relation to one another must be understood. The proposed study will investigate the relationship between early relational and overt aggressive behavior and later drug use, as moderated by gender and social competence. It will also examine the predictive relationship of aggressive behavior (relational and overt) and victimization (relational and overt) to drug use, as mediated by peer rejection and moderated by social competence. Subjects are a cohort of 659 students in a mid-western state, initially measured in the Fall of fourth grade and followed until the Spring of sixth grade. All data is self-reported. Data will be analyzed using multiple regression and structural equation modeling (SEM). The multiple groups approach of SEM will be used to test the moderating effects of social competence and gender early aggression-later drug use relationship, and the moderating effects of social competence on the victimization and aggression-peer rejection-drug use relationship.