OBJECTIVES: A rapid growth of health technology assessment (HTA) activities among researchers and physicians in Japan is observed since the mid-1980s. However, Japan lags behind Europe, Australia, and several Asian countries in implementing national HTA regulations. Although it is generally accepted that low healthcare costs and good health prevail in Japan, population aging, rising costs of medical technologies and slow economic growth rates necessitate rethinking the current HTA regulations. This study aims to evaluate the history and current situation of the Japanese HTA system, and what Japan needs to do in order to successfully implement national HTA regulations. METHODS: Past and current Japanese HTA regulation are assessed by analysing both English and Japanese publications and legal documents, as well as comparing these with the systems in other Asia-Pacific countries:  Australia, South Korea, Taiwan, Thailand. RESULTS: There are historical, social, and biological reasons why Japan has been successful at maintaining the world’s longest life expectancy and the lowest infant mortality at relatively low cost despite the lack of a comprehensive HTA system. However, implementation of HTA regulation would be a key lever in the health system in line with the new economic policy introduced by Prime Minister Abe in 2012. Looking at the legal and organisational structures, implementation and performance of Asia-Pacific HTA systems, a comprehensive HTA system for Japan is proposed. CONCLUSIONS: HTA systems have been rapidly developing in the Asia-Pacific over the last decade. Facing the current pressures on the health system, the question is not whether Japan should introduce a comprehensive HTA system but what measures she should adopt. The experience of other Asia-Pacific countries in implementing national HTA systems can help inform the development of an innovative national HTA system in Japan that could play a central role in the future of Japanese health care.