INTRODUCTION: Medical training refers frequently to sex and gender, yet these terms are often used vaguely and interchangeably with little critical engagement. We aimed to better understand the key discourses around sex and gender in medical training. METHODS: All verbal and written instances of gendered/sexed language, occurring in lectures, slides and provided written materials, within 1 year of preclerkship medical education at a single institution in Canada were recorded autoethnographically by a medical student. We analysed these instances using critical discourse analysis informed by anticolonial, feminist and queer theoretical perspectives, particularly contrasting the concepts of governmentality and ungovernability to better understand how sex and gender are deployed in medical training. RESULTS: Despite the proliferation of ostensibly queer- and trans-positive content in medical curricula, sex and gender were frequently communicated inconsistently and imprecisely. In addition to, and perhaps as a result of, this inconsistent use, we uncovered three key discourses of (1) gender policing, (2) misogyny and (3) gender legibility. Collectively, these discourses can illustrate how medical education governs and reinforces gender norms. DISCUSSION: The repetitive and everyday use of ill-defined and uncritical gendered and sexed language can be seen to discursively uphold systems of cisheteropatriarchy and transphobia within medicine. Trans and intersex bodies cannot be considered addendums to be tacked on to a foundation of cisnormative and inaccurate teaching in medical education. Institutional attempts to improve curricula must go beyond the addition of new modules, which can be undermined by otherwise cisheteropatriarchal understandings of sex and gender.