This study examined the effects of inhibitory control and normative beliefs about aggression and prosocial behaviour on aggression and prosocial behaviour in early childhood (ages 2-5). The extent to which normative beliefs about aggression moderated the relationship between inhibitory control and aggression was also explored. As part of a larger study, children (63) from three different preschools in Christchurch New Zealand completed computer-administrated tasks measuring inhibitory control. Beliefs about aggression were assessed using vignettes enacted with either toy figures or computer animated videos where children were encouraged to respond to each enacted scenario. A teacher rated measure was used to assess children’s aggression and prosocial behaviour. Inhibitory control was significantly associated with reactive physical aggression while normative beliefs about aggression was significantly associated with proactive physical aggression. Age was also found to have significant associations with inhibitory control and normative belief factors. No significant moderating relationship was found between inhibitory control, normative beliefs about aggression and aggression. This study highlights the differential associations of factors associated with aggression.