Boys show less adaptive behaviour and engagement than girls at school. Much research has examined gender differences in academic motivation to explain gender differences in school engagement. However, students engage in schools both academically and socially, and gender differences in social motivation may further contribute to the gender gap in academic engagement. In this study, 536 secondary school students in England (ages 13-14) reported their social achievement goals, academic achievement goals, and self-handicapping behaviours. Boys were more likely to adopt social demonstration goals, performance-approach and -avoidance goals, and reported greater behavioural self-handicapping. Moreover, structural equation models showed that social demonstration goals uniquely mediated the relationship between gender and self- handicapping, beyond the effect of performance-avoidance goals. Results highlight the importance of social achievement goals in explaining gender differences in self-handicapping. The findings suggest that educators need to attend to adolescents’ social goals in addition to their academic goals in secondary school.