Iodine is an essential trace element which is found in too low quantities in the soil in Germany. The resulting iodine deficiency in human beings is countered by iodine prophylaxis, essentially consisting of iodised table salt and the iodisation of agricultural animal feed. In iodine monitoring during the German Health Interview and Examination Survey for Children and Adolescents (KiGGS), the thyroid volumes of all children and adolescents from six years of age were determined using sonography. To assess iodine intake among the population, iodine excretion in the urine was also measured. The median ioduria value was 117 microg/l, putting it at the lower end of the scale of 100-200 microg/l recommended by the World Health Organisation. It can be concluded from these results that the iodine prophylaxis has been successful and that iodine intake has improved compared with the past. In accordance with the WHO recommendations there is no iodine deficiency in Germany any more; however, at the same time the population's iodine intake is at a relatively low level. The aim is at least to keep up what has been achieved, meaning that measures to improve iodine intake must not be allowed to slacken.