In the last decades, quality has imposed itself as a competitive need for firms, and also as a new normative parameter to guarantee the production process and the final product which the costumer buys. In the case of health services, the importance of quality is even greater because of the special value of this service, and the special relationship between the supplier and the costumer/patient. This relationship is often mediated by the State which has to provide the health services and the financial support for them. Thus, also in the case of Thermal Medicine, quality and its certification play a key role for the evaluation of the efficiency of the health service, and tend always more to be part of the health service accreditation process. In this article, we review the development of the idea of quality of service from the ancient Egyptian until the 20th century and we briefly recall the main European and Italian norms. We also examine the norms for the accreditation of the thermal health structures, and we review the main indicators of quality in Thermal Medicine, and the role of scientific research. Finally, we indicate that the cost of the lack of quality can be so prohibitive that the firms which do not follow the new standards, are put out of the market.