Recently, the role of science in policymaking has been attracting great interest around the globe. Scientific expertise is used for policymaking because of the society's trust in its neutrality and objectivity. Such trust, however, is not secured automatically. For instance, in the U.S., the Bush administration was criticized for handling scientific expertise inappropriately. At the international level, trust in the science of climate change was severely damaged recently. Under such circumstances, various efforts have been made to mend the damaged trust, and at the same time, measures have been taken overseas to institute general schemes to secure scientific integrity in policymaking. This article discusses such measures, including their historical backgrounds. It also suggests that Japan should begin discussion on this issue, taking into consideration Japan's own social and political context and at the same time pursuing international collaboration.