In 1948, the United Nations Convention on the Prevention and Punishment of the Crime of Genocide was official recognized under international law. Few, however, understand the role of international women’s rights organizations in the politics of the convention, the ratification process, and its application in the immediate postwar era. Rooted in their knowledge of Nazi atrocities and wartime activism, women’s organizations supported Raphael Lemkin’s campaign, but also critiqued the convention’s failure to address sexual violence and political repression of certain vulnerable groups.