This paper illustrates a role that bioethics should play in developing and criticizing protocols for breast cancer genetic screening. It demonstrates how a critical bioethics, using approaches and reflecting concerns of contemporary philosophy of science and science studies, may critically interrogate the normative and conceptual schemes within which ethical considerations about such screening protocols are framed. By exploring various factors that influence the development of such protocols, including politics, cultural norms, and conceptions of disease, this paper and the critical bioethics' approach it endorses illuminate and critically assess some of the competing worldviews informing protocol development. One of the frequently neglected worldviews in traditional bioethics' treatment of protocols concerning breast care is constituted by women's own views of their breasts and breast cancer, both within the technologically-oriented social practice of American medicine and in light of the social construction of their breasted experience in American society. This paper attempts to redress and critically assess this neglect on the part of traditional bioethics. Finally, in contrast to traditional bioethics, critical bioethics critically interrogates its own normative and conceptual commitments. In this final capacity, a critical bioethics' approach makes a valuable contribution to the evolution of bioethics.