Much has been written in the last decade about how we should understand the value of the sociology of bioethics. Increasingly the value of the sociology of bioethics is interpreted by its advocates directly in terms of its relationship to bioethics. It is claimed that the sociology of bioethics (and related disciplinary approaches) should be seen as an important component of work in bioethics. In this paper we wish to examine whether, and how, the sociology of bioethics can be defended as a valid and justified research activity, in the context of debates about the nature of bioethics. We begin by presenting and arguing for an account of bioethics that does justice to the content of the field, the range of questions that belong within this field, and the justificatory standards (and methodological orientations) that can provide convincing answers to these questions. We then consider the role of sociology in bioethics and show how and under what conditions it can contribute to answering questions within bioethics. In the final section, we return to the sociology of bioethics to show that it can make only a limited contribution to the field.