In medicine a gender perspective includes taking into consideration not only biology but also the cultural and psychosocial aspects of being a woman or a man. Unawareness or denial of gendered norms in society and/or of the power asymmetry between women and men can lead to resistance to gender issues and to the risk of gender bias in clinical medicine as well as in medical research and education. In a theoretical model presented in this paper the resistance and the bias risk are analysed in relation to assumptions about sameness/difference and equity/inequity between women and men. Such an analysis could facilitate the implementation of a gender perspective in settings and situations where resistance to gender issues is met.