Chapter 3 retraces the development of ethics expertise both in domestic contexts and in global governance arenas. It goes back to the first debates on the need to include a social and ethical assessment of science of technology in the late 1970s in the UnitedStates, in the context of new social challenges presented by technological innovations (such as organ transplantation), the publicising of several instances of bad practices on the part of medical professionals, and risks which arose when molecular biologists discovered they could create DNA sequences in the laboratory that did not naturally exist. In this context, isolated scientists and politicians, theologians and groups of engaged citizens felt the need to regulate medical and scientific activities.But while concerns over the ethics of medicine and science were initially voiced as a strong critique, bioethics eventually took the form of a new expert discourse, which became entangled with politics. This genealogy of the emergence of the notion of bioethical expertise is key to understanding the function payed by such experts in policymaking today.