<p>Mental health care is not free of gender biases. Some result from the conceptualization of certain psychological problems rooted in gender roles, from the biased interpretation of research findings, or from the fact that professionals are also immersed in a patriarchal culture. This paper aims to identify gender biases in clinical practice during psychological assessment, and to collect the solutions proposed in the literature to avoid them. A systematic review of the literature was conducted. The database search included articles published in English, Portuguese, and Spanish between 2000 and 2022, in the clinical or health field of psychology. Qualitative, quantitative, and mixed methods studies were included, and the Mixed Methods Appraisal Tool was used to assess their methodological quality. A total of 20 studies were selected. They mostly examined gender bias through case vignettes. Males were more likely to be diagnosed with antisocial personality, autism spectrum and hyperactivity disorder, and females with histrionic or borderline personality, and anorexia nervosa disorder. This diagnostic difference is due to the use of diagnostic criteria consistent with social gender constructs of what is understood as masculine and feminine. Gender biases may lead to invisibilization or over-pathologization of mental health problems, as clinical practice is not exempt from patriarchal reductionism.</p>