This research examines student perceptions of teacher, peer and parent relationships in New Zealand schools, and how these relate to aggressive behaviours and attitudes. A path analysis was used to see if school climate mediates the association between the quality of within school relationships and aggression. Student perceptions of relationships with their teachers and peers, and parental involvement with school were all significantly interrelated. The quality of teacher-student relationships was the strongest predictor of school climate, which in turn predicted both aggressive behaviour and proaggressive attitudes. This research suggests that improving teacher-student relationships may have the greatest impact in reducing physically aggressive behaviours and attitudes in schools.