Urinary iodine excretion was examined in 645 patients at Bad Hall, both before and after undergoing iodine balneotherapy. The results indicate that in spite of iodized salt prophylaxis there is still an insufficiency of iodine supply in Austria. No essential differences were detected between individual regions of Austria. After completion of various types of iodine balneotherapy each lasting four weeks, the iodine excretion of all patients was higher than the minimum value proposed by WHO.