Individuals who are women are members of a group, "women," yet they are also very different from each other. Is there one womanness or many? Realists say that there is one womanness whereas nominalists say that there are many. Although nominalism is the more popular position among feminists, and realism is usually dismissed, Mari Mikkola has recently proposed that gender realism should be treated as a serious metaphysical option. In this chapter I evaluate the arguments for nominalism. I identify five separate arguments and conclude that, although not all of the arguments are successful on their own, the combined effect of the ones that are successful is to make a strong case for gender nominalism. Feminists are right therefore to reject realism and adopt nominalism. At the end of the chapter, I briefly address the question "Why does this debate matter?" If the debate between gender realists and gender nominalists is no more than metaphysical or theoretical bookkeeping, why should feminists care about adopting one side or the other?