The outcome of a referral for which the law itself makes provision, this report is a landmark in the activities of the Parliamentary Office for the Evaluation of Scientific and Technological Choices. It is based upon some forty interviews that took place between May and December 1998 and also takes into account the views recently emanating from various authorities (the Council of State, the National Consultative Committee on Ethics, the Academy of Medicine, the European Ethics Group, and so on). It seeks to identify problems of application (related in particular to the delay in issuing regulations) without prejudicing any future decisions by the government, and puts forward possible solutions. With regard to transplants, the main emphasis is placed on the need for better informing donors and acceptors, the law’s unsuitability in respect of new transplant techniques, the value of European co-operation in health and safety, and the lack of clarity of the rules governing the taking of organs both for therapeutic purposes and for medical and scientific reasons. Medical support for reproduction is analysed, notably as regards the far-reaching changes resulting from the development of ICSI, an in vitro fertilisation technique for which there was no prior experimentation, the problems raised by the existence of large number of embryos and the choices available to the government in terms of embryo research having regard to recent scientific progress. The report stresses the inadequacy of the controls placed on establishments and practitioners. It concludes by stressing the need for international and European co-operation aimed at harmonising both principles and procedures.