Background & Aims: Despite adequacy of dietary iodine intake in the Islamic Republic of Iran, the prevalence of goiter is still high in certain parts of the country such as West Azarbaijan province.  This investigation was undertaken to evaluate urinary iodine excretion (UIE) and prevalence of goiter among (10-17 years-old) schoolchildren in Urmia County.

Materials & Methods: Schoolchildren (n=500 gender: girls) were enrolled by random cluster sampling from different schools districts in Urmia. Studied population comprised 158 primary schoolchildren, 257 secondary schoolchildren and 85 high schoolchildren. UIE was assessed by the Sandell-Kolthoff method while prevalence of goiter determined by palpation.

Results: Median UIE in Urmia’s education districts (1&2) were 145 µg/L and 142 µg/L, respectively. Median UIE in high school children was significantly higher than those in primary- or secondary schoolchildren. Prevalence of goiter in primary - , secondary- and high school were 9.5%, 15.2% and 8.2%, respectively.

Conclusions: The present study reveals that average goiter prevalence among schoolchildren in different education levels was 12.6%. This was markedly higher than the value (0.4%) reported by the 4^th national survey in 2006. High prevalence of goiter among secondary schoolchildren is possibly associated with pubertal hormonal changes. Further should be conducted to evaluate distribution of thyroid antibody and autoimmune thyroiditis among school-age children Urmia County.