Background and Objectives: Iodine deficiency disorders have been one of the main health-nutritional problems in Iran for many years. Prior to the iodine-supplementation program, Ardabil province was one of the regions with endemic goiter in Iran. The program of control and prevention of iodine deficiency has been performed here since 1989 through production, distribution and consumption of iodized salt. This study was performed in 2001 on 7-10 years-old pupils of Ardabil as a part of national monitoring survey of iodine deficiency control.

 Methods: In a cross sectional- descriptive study, 1200 students (equal number of boys and girls) were selected randomly. The prevalence of goiter was determined by clinical examination and according to WHO classification. Urinary iodine content was determined in one tenth of the cases using digestion method.

 Results: Total goiter rate was 9.3 in all the subjects (10.7% in girls and 7.9% in boys). Median urinary iodine was 18.8µg/dl. In 80.7% of the cases urinary iodine was above 10µg/dl and was less than 5µg/dl in 4.2%. Urinary iodine below 2µg/dl was not observed.

 Conclusion: The results showed that the rate of goiter among pupils has significantly decreased since 1996 and urinary iodine levels in schoolchildren of Ardabil complied with WHO index. So, Ardabil province can be considered as an “iodine deficiency free” zone.

 Background & Objectives: Goiter prevalence in school age children is an indicator of the severity of iodine deficiency disorders (IDD_S) in the society and a goiter prevalence ≥5 % in school age children indicates a public health problem. In area of mild to moderate IDD_S, measurement of thyroid volume by ultrasonography through observation is preferrable to population for grading goiter. Considering the importace of this issue, because of being mountainous and lack of this method's application for determining the incidence of goiter this study was desinged.

 Methods: In this descriptive – analytical study, thyroid volumes of 230 boys between 12 to 15 years old were measured by portable ultrasonograph in Tabriz. Also urinary iodine concentrations were determined by method A (Sandell-kolthoff reaction).

 Results: Mean of subjects’ thyroid volume was 8.12 ±2.21 ml and with latest references of Iran and WHO/NHD, goiter prevalence was taken based age 51.7 % and based surface body 81.1 %. Urinary iodine median of tested samples was 15.2µg/dl and iodine deficiency prevalence was 29.1 % . There was no significant correlation between urinary iodine and thyroid volume.

 Conclusion: Large thyroid volume of middle school boys in Tabriz is probably due to iodine intake deficiency in the first years of their life. Also, the role of goitrogenic factors and effect of climate condition on thyroid volume and goiter prevalence of middle school boys in Tabriz shouldn't be ignored. Further studies are recommended for determination of a local reference for thyroid volume Also it is necessary to be sure from consumption of iodine salt and its standardization.