In recent years, governmental policy changes have exerted significant impact on the structural transformation, role diversity and commercialisation of national quality assurance agencies in many nations. Due to policy change, ongoing structural transformation and emerging roles, four national quality assurance agencies in Australia, Japan, Malaysia and Taiwan were selected as case studies. The study presents three major findings. First, although a state-controlled governance model remained popular in all cases, the university-led and supermarket models were chosen due to changes in policy. Second, case agencies intended to develop new roles in order to respond to policy change and public demands, particularly enhancing professionalism, redefining the relationship with universities as partners, strengthening the linkage with international quality assurance networks, providing quality assurance services with foreign providers. Third, autonomy and independence remain a considerable challenge for quality assurance agencies.