Scientists have genders. Should this fact matter to epistemologists of science, who investigate the nature of empirical justification? Some have suggested that it should matter because the contingent history of Western science — an activity largely dominated by men — has fostered a system of basic assumptions and methods that is conceptually inhospitable to women’s experiences and the sorts of knowledge women are especially well-situated to obtain. Others have suggested that traditional epistemology, appropriately pursued, reveals ways that the gender or social location of inquirers can function as an epistemic resource, thereby increasing the predictive and explanatory tools available to modern science. We evaluate these suggestions, drawing upon the writings of both traditional and critical epistemologists, as well as upon historical case studies of particular sciences (including genetics, chemistry, primatology, endocrinology, and quantum physics). Topics covered might include the following: To what extent have gender biases affected the practice of science and content of scientific knowledge? Have factors related to gender compromised scientific objectivity? How has scientific thinking about sexual differences influenced on-going debates about gender in society? To what extent would a “gender neutral” approach to science be desirable?