This paper is an empirically backed contribution to the current ‘failing boys’ debate in regard to their lower educational success. The cross-sectional analysis focuses on two possible factors behind the lower educational success of boys in secondary school: school alienation and patriarchal gender-role orientations (as an expression of the ‘hegemonic masculinity’). School deviance on the behavioural level is considered as a main mediator between these factors and educational success. Furthermore, teaching style, peer attitudes and social origin are taken into account as important factors of educational success. Analyses are based on a Swiss mixed-method study (questionnaires among 872 eighth-graders, group discussions, class room observations). Results indicate that the gender gap in educational success is caused partly by boys being more alienated from school and preferring patriarchal gender-role orientations. The impacts of these factors on educational success are mediated by school deviance. An authoritative teaching style can largely reduce school alienation.