In Croatia a law requiring obligatory iodination of all salt with 10 mg KI per kg of NaCl was proclaimed in 1953. After first ten years of implementation a threefold reduction of goiter prevalence was recorded. Presented study indicates that, four decades later, mild iodine deficiency still persists, keeping goiter prevalence among schoolchildren between 8% and 35%. In continental parts of Croatia 69% to 86% of children had urinary iodine excretion above 5 micrograms/dL, while only 17% to 34% had it above 10 micrograms/dL. In Zagreb, 5% to 13.2% of children had thyroid volumes above the upper limits for their age. Control of salt produced in Pag revealed the average KI value of 8.3 mg/kg. On the basis of these results Croatian Ministry of Health proclaimed, on October 9, 1996, a new regulation requiring 25 mg KI in each kg of NaCl.