This article examines reproductive struggles and debates in late colonial and early postcolonial Kenya by reconstructing the history of the short-lived Affiliation Act, a law that granted all single women the right to sue the fathers of their children for paternity support. In 1959, the colonial government enacted this racially inclusive law in a bid to address the social problem of "illegitimacy" through familial channels, and to demonstrate the government's commitment to a nonracial future. The passage of the Affiliation Act, and women's subsequent use of it generated intense debates over the relative powers of men and women, and the value of the "modern" and "traditional" in postcolonial Kenya. Through denouncing and engaging the Affiliation Act, Kenyans argued over who should control women's sexuality, and who should bear the responsibility for, and reap the rewards of, their fertility. They also contested the vision of gender relations that should be embodied in African nationalism and should be promoted by the new Kenyan nation. This article demonstrates how material struggles stemming from pregnancy and surrounding child rearing—"the politics of the womb"—have been important to the elaboration of gender and political relations in postcolonial Africa.