Until recently, modern biotechnology aroused debate mainly in the field of food applications, around a number of genetically modified plants such as maize or soya. Various surveys indicated that medical applications of biotechnology were receiving far more support from the general public than applications in the field of agriculture and food production (Durant et al, 1998; Gaskell and Bauer, 2001). However, some specific medical applications are not without controversy, especially the new regenerative medical techniques such as xenotransplants, cloning and stem cell research. This chapter will examine the recent evolution of public debate around these techniques, based on an analysis of the situation in three countries, Canada, France and Germany, in order to reach a better understanding of the role societal processes play in the development and implementation of new technologies.