This review assesses Japan's public health system, highlights areas of strength and weakness, and makes a number of recommendations for improvement. The review examines Japan's public health system architecture, and how well policies are responding to population health challenges, including Japan's ambition of maintaining good population health, as well as promoting longer healthy life expectancy for the large and growing elderly population. In particular, the review assesses Japan's broad primary prevention strategy, and extensive health check-ups programme, which is the cornerstone of Japan's secondary prevention strategy. The review also examines Japan's exposure to public health emergencies, and capacity to respond to emergencies as and when they occur.