Through the difficulties encountered during the previous centuries in order for an animal to be recognized as a sensitive being, we saw the evolution of society's attitudes change from antiquity to our present day. Over the past twenty years animal testing has first evolved within a progressive regulatory framework reinforced by an ethical thinking which has, since 1990, led to the establishment of the ethics committees. The dialogue between these committees and researchers has led to the recovery of principles previously ignored such as the 3Rs (Replace, Reduce, Refine). This in turn has led to the application of improving experimental conditions, the progressive decrease in the number of animals used through a wise use and the replacement of animals by in vitro techniques in the very preliminary stages of research. Progress remains to be done, but the evolution of European regulations being amended, the formalization in France of ethics committees and the establishment of the National Ethics Committee should further contribute to the improvement of animal welfare in experimental research.