The literature on gender specific educational achievement indicates that primary school teaching has become more and more a female profession and that the lack of male role models in primary education may negatively influence the school achievement of boys. This study examines if children's math test scores are higher if they are taught by a teacher of their own gender. For this purpose we use unique Dutch data on 2586 primary school children and identify the same-gender effect by estimating an innovative within class between child gender estimation model. The empirical findings indicate that children's math performance is not influenced by the gender of their teacher.