Based on the case of Caster Semenya, I argue in this paper that the practice of Gender Verification Testing (GVT) in professional sports is unethical and pointless. The presumed benefit of GVT—ensuring fair competition for female athletes—is virtually nonexistent compared to its potential harms, in particular the exposure of individual athletes to a largely interphobic public. GVTs constitute a serious incursion on the athlete’s dignity, autonomy, and privacy; an incursion that cannot be justified by the appeal to fairness. My argument (...) will proceed in four steps. In sections 1-5, I provide background information on the definition of intersexuality, the history and methods of Gender Verification Testing, and the performance gap between men and women in professional athletics. In sections 6 and 7, I develop my main argument against GVT. In section 8, I offer a supplementary argument against GVT from the history of “gender engineering” in professional sports in the 1970s and 1980s. In section 9, I briefly consider the suggestion that the presence of intersex athletes in professional sports would force us to abandon gender segregation. (shrink)