This article examines lesbian teachers' negotiation of the public/private boundary in the school, focusing on identity management in the context of the heterosexualised space of this public institution. The study is based on interviews conducted with six lesbian teachers working in London secondary schools. I examine the teachers' responses, and the ways in which they mediate the "polite" silences in relation to lesbian and gay sexuality, as situated in a framework of liberal tolerance found in public and political domains. Sex and relationship education guidance, as well as recent policy initiatives concerned with homophobic bullying, play an important role in framing the discourses around sexuality in the school. However, the continuation of problems with heterosexism and homophobia in schools is evident. I argue that the lesbian teacher's negotiation of the public/private boundary and of power relations involves the heightened importance of a "good teacher" identity, and an emphasis on professionalism. While these teachers do not speak of direct victimisation or abuse, much change needs to take place to transform the school into a place where lesbian and gay sexuality may be named without fear. (Contains 4 notes.)