The legal consequences of the precautionary principle (PP)have been, for several years, the cause of much controversy. We will not go back over these debates which, certainly, would not help clarify the legal indeed, even civilian considerations. To stick to the assigned title, we shall skim through the legal aspects of the PP in an attempt to present developments on the matter, developments which may appear, either very slow and worrying for some, or too fast but just as worrying for others. Rather than reasoning in terms of a swift propagation of the PP or in terms of reservation with regard to its acknowledgement or non acknowledgement, we thought it wiser to present, in concrete terms, the legal considerations of the PP on the part of the different authorities. In doing so, not only do we have in mind the practical confirmation of the PP by the authorities “making” the law, i.e. the “lawmakers”, in a general sense, but also the administrative independent authorities and “judges”. By standing in favour of the PP, we believe that the report is somewhat discouraging from a national point of view whereas it is more encouraging from a European perspective. The genuine advances in this field are neither French nor international but come from the European community with, yet, a serious reserve.