Publisher Summary Iodine deficiency disorders (IDD) have been recognized as one of the public health problems in Thailand since 1953. Several surveys had been conducted since 1955 to assess the magnitude of the problem and to find out appropriate strategies. Iodization of salt has been set as the main strategy and a salt iodization program was first launched in 1965. The situation of IDD, using goiter as indicator, was gradually decreasing while there was high prevalence of protein energy malnutrition (PEM). Therefore, the priority shifted to PEM alleviation and the support for IDD control decreased, resulting in the re-emergence of IDD in 1987. The Department of Health recognized the situation and established the National Iodine Deficiency Disorders Control Program (NIDDCP) in 1989, which covered 15 target provinces and gradually expanded until the whole country was covered in 1991. IDD had been recognized as a public health problem in Thailand for more than 50 years. Salt iodization is the main strategy to remedy this. Salt producers are the key players and their active participation in the program is very much needed. An effective system for the assessment of the situation and monitoring of the program is necessary. There is a need to raise public awareness about the benefits of iodized salt use, from household to national level. The lesson learned is the program must be continuously implemented to ensure sustainable elimination of IDD.