Iodine deficiency disorders (IDD) in Indonesia is still prevalent in endemic areas, where soil and water are lack of iodine. It has been estimated that 54 million of Indonesian people are living in endemic area, therefore susceptible from IDD. The consequences of IDD are goiter, cretinism, lower intelligence, mental retardation and delayed physical development that ultimately reduce Indonesian human resources. The relationship between iodine deficiency and low intelligence quotient (IQ) is straight forward. Meta analysis from 18 studies revealed that people living in iodine deficient areas had 13.5 IQ point lower than their counterparts. Several measures have been adopted by Indonesian government to eradicate IDD, especially to prevent new cretins. However, cretinism like top of iceberg is the smallest proportion; at the base much more people are suffering from hypothyroidism with lower IQ scores. The relationship between iodine and intelligence will be discussed in this paper.