This paper reviews the current system of regulation and assesses its effectiveness in the health-care system of Thailand. In order to achieve this, extensive documentary reviews were performed and supplemented by in-depth interviews. We found the existing regulatory framework to be fairly comprehensive with rules and roles firmly established. Regulations cover almost all relevant private and public organisations including individuals. However, the incomplete performance of regulatory functions was detected resulting in problems of overburdened staff and delays in performance of functions. Our recommendations propose the promotion of professional ethics and continuing education, an effort to narrow the gap between expectation and reality through public education, and the empowering of consumer organisations. The increasing popularity of medical lawsuits and professional insurance, which in part reflects the imperfect administration of the system, highlights the need for careful consideration of how best to handle the increase in complaints. The mapping of the regulatory system in this paper, together with the discussion of how to cope with the expansion of medicine as a business and with greater consumerism, will be of interest to other middle income countries that seek to reform and strengthen their regulatory system.