While medicine has made remarkable progress over the last decades, its development has also raised numerous ethical and legal issues. In this context, the question arises as to what framework is needed for research, organ transplants, and medically assisted reproduction. A balance has to be found between scientific freedom, the imperatives of public health and the protection of people ' welfare, rights and human dignity. Those questions have led to the adoption of multiple national laws as well as ethical and legal norms at the international level. The judiciary is also often involved in settling legal issues raised in this context, long before the legislature manages to provide a legislative or regulatory framework. In this analysis of the role of the judges in bioethics, the present paper aims at offering a comparative view of case law in different countries (France, Germany, Switzerland and the United Kingdom) concerning the status of the embryo. In life sciences, the status of the embryo is at the heart of the debate as it determines the very notion of human life. The hypothesis suggested by the organisers of the workshop fbr which this paper has been prepared was that a custom was emerging from national cases related to this question. Our analysis concerning the status of the embryo does not confirm this hypothesis. On the contrary, courts are reluctant to take the place of the legislature in dealing with this delicate issue. Even when judges take novel positions on the protection of the embryo, we can notice a wide range of judicial solutions that raise a serious doubt about the actual existence of an international custom that could be binding in the various legal orders.