The science of genomics – the exhaustive investigation of genomes and indeed of all genes – will play an essential role in the 21st century. Based upon biological information technology, it offers a wide range of possibilities in medicine and pharmacology; the use of proteins in pharmaceutical research; gene therapy; genic vaccination; pharmaco-genomics (adapting treatment to the genetic characteristics of the patient); molecular diagnostics of infectious diseases and of genetic predispositions, using "biochips", and so on. The present report describes all these new technologies that should make it possible to treat the causes of diseases rather than their symptoms. It also lists the choices that will have to be made if France is to benefit from the genomic revolution, while controlling its consequences. As far as research is concerned, it stresses the need very rapidly to develop the study of proteins and to bring about the production of French biochips. In the industrial field, it reviews the aid available to new businesses in biotechnology concerned with bio-incubators and biological research centres; it also tackles the strategic problem of patents. Finally, examining the problems that biology in the 21st century will put before our society, it sets out ambitious recommendations for the professional training that will have to be provided. As far as predictive medicine is concerned, it calls for caution and suggests preserving the right not to know and the right not to pass on knowledge. During the 20th century France was able to mobilise its resources so as successfully to take up the scientific, technical and industrial challenges of power and speed. The issues in the life sciences are of equal importance; within this vast field the questions of health and therapeutics will occupy a major place in our society. Those with political responsibility, at every level, must encourage genomics in order to provide our country with the resources it needs to find its place in this sector.