The aim of our study was the evaluation of goiter prevalence in the children in Poznań and surrounding towns and villages. In 3065 children 4-16 years old the thyroid size and serum concentration of T3, T4 and TSH were determined. Our results indicate that the goiter prevalence in the group of investigated children was 20%. We also observed that the changes in the concentration of thyroid hormones and TSH were not associated with the clinical symptoms of thyroid gland dysfunction.