This paper explores how single-sex and co-education affect girls' and boys' gender beliefs and relations. Earlier research in sub-Saharan Africa suggests that co-educational schools are sites of male intimidation, violence, and unequal power relations. Meanwhile single-sex education is said to enhance girls' self-confidence, improve their academic scores, and enable them to act as leaders, in a safe space, absent of boys. However, recent qualitative research in the Zambian Copperbelt suggests that co-education may actually be more conducive to gender equality. Seeing girls demonstrate equal competence in mixed-sex classes can undermine gender stereotypes, on the part of girls and boys alike. The research also calls into question assumptions that single-sex education is necessarily better at enhancing girls' self-confidence and protecting them from intimidation and male violence.