Previous research has suggested that females hold “expressive” social representations of aggression and males hold “instrumental” representations [e.g., Archer and Parker (1994): Aggressive Behavior 20:101–114; Campbell et al. (1992): Aggressive Behavior 18:95–108]. There is also evidence to suggest that an instrumental representation is associated with higher levels of actual aggression [e.g., Archer and Haigh (1996): British Journal of Social Psychology 35:1–23; Campbell et al. (1993): Aggressive Behavior 19:125–135] and that although males employ more physical aggression, females use more indirect aggression [Lagerspetz and Bjorkqvist (1994): Plenum Press]. In light of these findings, the present study aimed to (1) devise questionnaires measuring social representations of physical, verbal, and indirect aggression, suitable for use with children aged 7 to 11 years; (2) examine sex and age differences in these questionnaires; and (3) compare representations of physical aggression with representations of indirect aggression for both boys and girls. Results showed that compared with girls, boys held more instrumental representations of all three forms of aggression, whereas compared with boys, girls held more expressive representations. Likewise, children aged 10 to 11 years held more instrumental representations of all three forms of aggression compared with children aged 7 to 8 years. There were no differences between representations of physical vs. representations of indirect aggression for girls or for boys. Sex and age differences were discussed in terms of sex roles and a developmental change in children’s views on aggressive retaliation. In addition, previous research suggesting a link between representations and actual aggression was questioned. Aggr. Behav. 26:442–454, 2000. © 2000 Wiley-Liss, Inc.