The authors investigated the patterns of reactive and proactive aggression exhibited by young male (N = 604) and female (N = 544) adolescents in Singapore. Self-report measures of reactive and proactive aggression, behavioral and emotional adjustment, parenting styles, and delinquency were administered to students aged 13–14. Using cluster analysis, three distinct patterns of aggression emerged: a low aggressive group, a combined aggressive group with high reactive and proactive aggression, and a reactively aggressive group with low proactive and high reactive aggression. The two aggressive groups showed similar disturbances in adjustment and delinquency, but the combined group showed the greatest disruptions. Findings indicate cross-cultural stability of patterns of aggression as well as the usefulness of the reactive/proactive distinction in early identification of individuals with adjustment problems.