Although precision medicine cuts across a large spectrum of professions, interdisciplinary and cross-sectorial moral deliberation has yet to be widely enacted, let alone formalized in this field. In a recent research project on precision medicine, we designed a dialogical forum (i.e. ‘the Ethics Laboratory’) giving interdisciplinary and cross-sectorial stakeholders an opportunity to discuss their moral conundrums in concert. We organized and carried out four Ethics Laboratories. In this article, we use Simone de Beauvoir’s concept of moral ambiguity as a lens to frame the participants’ experience with fluid moral boundaries. By framing our approach through this concept we are able to elucidate irremediable moral issues that are collectively underexplored in the practice of precision medicine. Moral ambiguity accentuates an open and free space where different types of perspectives converge and can inform each other. Based on our study, we identified two dilemmas, or thematic interfaces, in the interdisciplinary moral deliberations which unfolded in the Ethics Laboratories: (1) the dilemma between the individual and the collective good; and (2) the dilemma between care and choice. Through our investigation of these dilemmas, we show how Beauvoir’s concept of moral ambiquity not only serves as a fertile catalyst for greater moral awareness but, furthermore, how the concept can become an indispensable part of the practices of and the discourse about precision medicine.