The purpose of this article was to determine the socialisation antecedents of socio-moral approval of aggression (SMAA). In Study 1, we assessed factorial structure and reliability of the SMAA with a sample of 355 students who reported on the extent to which they approved of six forms of aggressive behaviour and six justifications of aggression. Two-factor solutions were obtained with regard to forms and justifications of aggressive acts. Thus, approval of extreme and minor aggression was distinguished as well as legitimate and illegitimate justifications of aggression. In Study 2, we tested the path models of the socialisation antecedents that contributed to the high approval of minor and extreme aggressive acts as well as legitimate and illegitimate justifications of aggression. Data were collected from 173 undergraduate students. Path analyses showed that high levels of approval of extremely aggressive acts and of illegitimate justifications of aggression were preceded by a sequence of negative life events, beginning with frequent misbehaviour in childhood, corporal punishment used by parents and ending with delinquency in adolescence. The approval of minor aggression had little relation to socialisation factors apart from a detrimental effect of psychological aggression while approval of legitimate justifications of aggression had no socialisation antecedents.