© 2015 The Foundation for Professionals in Services for Adolescents. This study used prospective birth cohort data to analyse the relationship between peer aggression at 14 years of age and educational and employment outcomes at 17 years (N=1091) and 20 years (N=1003). Participants from the Western Australian Pregnancy Cohort (Raine) study were divided into mutually exclusive categories of peer aggression. Involvement in peer aggression was reported by 40.2% (10.1% victims; 21.4% perpetrators; 8.7% victim-perpetrators) of participants. Participants involved in any form of peer aggression were less likely to complete secondary school. Perpetrators and victim-perpetrators of peer aggression were more likely to be in the 'No Education, Employment or Training' group at 20 years of age. This association was explained by non-completion of secondary school. These findings demonstrate a robust association between involvement in peer aggression and non-completion of secondary school, which in turn was associated with an increased risk of poor educational and employment outcomes in early adulthood.