Despite research on peer dynamics in mainstream classrooms and in mental health interventions, investigations of peer dynamics in self-contained classrooms for students with emotional and behavioral disorders (EBD) are limited. This study examined the influence of classroom behavior norms on individual behavior in a school for students with behavior challenges. Ratings of respectful behavior and rule-following behavior were collected for each marking period of one academic year during reading instruction and during lunch at both individual and classroom levels. Two sets of hierarchical linear models examined whether individual behavior trajectories were independent of classroom grouping (i.e., unconditional growth models) and whether classmate behavior norms predicted individual behavior (i.e., conditional growth models). Overall, individual trajectories for respectful behavior and rule-following behavior were not dependent on classroom groupings. However, across behaviors and settings, classroom norms significantly predicted individual behavior. These findings extend classroom norms research into an EBD setting and suggest that classroom norms may promote or inhibit positive behavior within self-contained classrooms for students with EBD. Behavior support programs within self-contained settings should account for influence of classroom norms (e.g., incorporation of group contingencies) to enhance social functioning of students with EBD.