Bullies, victims, bully-victims, and control children were identified from a sample of 1062 children (530 girls and 532 boys), aged 10 to 12 years, participating in the study. Their reactive and proactive aggression was measured by means of peer and teacher reports. Peer and teacher reports were more concordant with respect to reactive than proactive aggression. Comparing the children in different bullying roles in terms of their reactive and proactive aggression, bully-victims were found to be the most aggressive group of all. For this group, it was typical to be highly aggressive both reactively and proactively. Although bullies were significantly less aggressive than bully-victims, they scored higher than victims and controls on both reactive and proactive aggression. However, observations at the person level, i.e., cross-tabulational analyses, indicated that bullies were not only overrepresented among children who were both reactively and procatively aggressive but also among the only reactively aggressive as well as the only proactively aggressive groups. Victims scored higher than control children on reactive aggression, but they were not proactively aggressive. Furthermore, even their reactive aggression was at a significantly lower level than that of bullies and bully-victims. Aggr. Behav. 28:30-44, 2002.