In recent educational discourse, public schools can be seen as sites of feminine power, as the majority of teachers are female and some gains have been made in girls' school achievement. However, some theorists argue that schools are too feminine, and thus boys' achievement is at risk. This article refutes this claim, and shows that schools are still fundamentally patriarchal structures. Drawing on feminist new materialisms thinkers, particularly Barad's ideas of intra-action and posthuman performativity in relation with Alaimo's concept of the material memoir, this article considers the experiences of the menstruating teacher, and explores how new materialisms can help researchers trace the complex, ongoing ontological relationship between the teacher and the materiality of the school.