Over the past 25-30 years, a number of journal articles and books have been published on the history of sex testing, offer a critique of the various methods employed to determine sex/gender, or provide a feminist criticism of sex testing/gender verification policies. Moreover, white papers published in medical journals have outlined the limits of scientific technologies to determine sex/gender. Scholars aware of this extant literature will find much of the historical trajectory, critique, and argument outlined in Sex Testing quite familiar. Sex Testing: Gender Policing in Women’s Sports by Lindsay Parks Pieper collates this research, providing an exhaustive history of sex testing policies in international sports competition from the 1930s to the 2000s. Driven by fears of men posing as women in athletic competition, the International Olympic Committee (IOC) and other international and national sports governing bodies developed, implemented, and defended testing athletes in women’s competitions, ostensibly to ensure fairness and a level playing field. Similar to arguments put forth previously by feminist scholars, Sex Testing illustrates how nationalism, particularly during the Cold War, gender ideologies, including the notion of female physical inferiority, and notions of the sex/gender binary shaped sex testing policies and justified their continued use, despite objections by the medical community.