Goiter prevalence and urinary iodine excretion levels were assessed in 605 school-children (301 males and 304 females), aged 6-11 years, living in the Antalya region, a well known endemic goiter area in Turkey. Goiter prevalence was evaluated by clinical examination and ultrasound of the thyroid gland. Urinary iodine levels were expressed as mu g/g creatinine, Goiter by inspection and palpation was found in 35% (n = 212) of all subjects, in 37.5% (n = 114) of girls and 32.5% (n = 98) of boys. Iodine deficiency of moderate degree was detected from the point of goiter prevalence. With regard to the upper limits of reference thyroid volumes reported by WHO and ICCIDD, goiter by ultrasonography was found in 34% (n = 206) of all subjects, in 36.8% (n = 112) of girls and 31% (n = 94) of boys. Median iodine/creatinine ratios of all subjects, and goitrous and non-goitrous subjects, were 64.1+/-20.1, 62.8+/-21.8 and 64.9+/-19.1 mu g/g, respectively. Urinary iodine excretion levels revealed mild iodine deficiency in the region. No significant correlation was observed between urinary iodine excretion levels and thyroid volumes (r = 0.12, p > 0.05), Iodine deficiency of mild to moderate degree in schoolchildren aged 6-11 years was detected in Antalya, It was concluded that urgent measures must be undertaken to eradicate iodine deficiency in the region.