Social consensus is considered to be a necessary condition for a policy to be introduced and implemented effectively. This is the case with the approval, regulation and prohibition of certain advanced medical research and technology, especially when they could invoke moral disputes in society. Public policies on organ transplantation, definition of death, euthanasia, genetic screening and diagnosis, and human stem cell research are recent examples. The concept of consensus, however, is elusive, along with the measures to secure it. Technocratic decision making, as a paternalistic activity frequently led by experts, sometimes poses a challenge to democratic decision making, supposedly based on a well-informed and rational public. It also remains to be proved whether public involvement in policymaking can be a solution to ethical value conflicts in society. From the perspective of policy sciences, this paper first introduces the concept of consensus, especially consensus on moral issues in pluralistic societies, and its implications to public policy, including citizen participation in decision making. Then, it briefly explains the historical background with which social consensus and public involvement have increasingly flourished in the field of technology assessments and technology policy making, including biomedical technology. Next, major institutions, governmental and nongovernmental, involved in the ethical aspects of medical research and technology, are presented along with their efforts for citizen participation. Finally, the paper discusses some of the future agendas on this issue.