Knowledge hiding – intentionally concealing knowledge from a colleague who requested it – is often damaging for individuals and organizations. Amongst the factors explaining knowledge hiding, one has been overlooked, despite being an important lens for understanding employee behaviours: gender. In this article, we investigate its relevance by examining whether and how gender shapes two complementary aspects of knowledge hiding behaviour: frequency of hiding, and the approaches that knowledge hiders employ to do so. Building on extant literature about gender roles at the workplace, we suggest that the social roles into which women and men are socialized, and the sanctions they face if they behave incongruently with these roles affect both aspects of knowledge hiding. We explore these ideas in a multi‐wave study of full‐time employees based in the United Kingdom (n = 449). Our findings suggest that men hide their knowledge from colleagues more frequently. In addition, both women and men hide knowledge in a way that is congruent with the expectations of others regarding their social role: that is, women use evasive hiding and playing dumb more than men, while men use rationalized hiding more than women. A male‐dominated context reduces these differences between genders.