Background: Differential responses in terms of gender and antisocial behaviour in emotional reactivity to affective pictures using the International Affective Picture System (IAPS) have been demonstrated in adult and adolescent samples. Moreover, a quadratic relationship between the arousal (intensity) and valence (degree of unpleasantness) has been suggested. The picture perception methodology has rarely been applied to middle school-aged children. We examined the subjective ratings of emotional reactivity in children for: i) the relationship between arousal and valence, ii) gender differences, and iii) its association with measures of antisocial behaviour. Method: Twenty-seven IAPS pictures were selected to cover a wide range of affective content and were individually administered to a non-referred community sample of 659 7-11-year-old children using a paper-and-pencil version. Concurrent symptoms of conduct disorder, oppositional defiance and psychopathy were collected from multiple sources (teacher-, parent- and self-report). Results: A quadratic relationship between arousal and valence, similar to that previously reported in adults, was demonstrated. A gender difference was found for valence ratings, with girls rating aversive pictures more unpleasant than boys. No gender differences for arousal ratings were found. A significant difference was found between groups scoring above and below cut-off scores on measures of antisocial behaviour. Children above cut-off reported lower arousal to unpleasant pictures, but higher arousal to pleasant pictures. Conclusions: We confirmed that a paper-and-pencil version of the IAPS for evaluating emotion response to affectively valent and arousing stimuli can be used in school settings and that comparable gender differences in emotional reactivity can be found in children. The differential emotional reactivity of children above cut-off on measures of antisocial behaviour suggested these symptoms to be associated with a combination of increased reward and decreased punishment sensitivity.