After a successful programme to prevent iodine deficiency disorders in the Islamic Republic of Iran in the 1990s and early 2000s, evidence emerged that urine iodine levels in the population were falling. This paper reviews efforts to monitor and enforce the iodization of salt production and shows the resulting improvements in iodization levels of factory table salt and in urine iodine concentrations of primary-school children in East Azerbaijan province. Reaching targets for elimination of iodine deficiency disorders requires efficient monitoring of the population’s iodine levels combined with monitoring of the iodine content of table salt and enforcement of iodization regulations.