The main cause of endemic and sporadic goiter is a deficiency in the dietary supply of iodine. However, iodine deficiency is not the only cause of goiter. This paper reviews present knowledge on the role of naturally occurring goitrogens in the etiology of goiter. Vegetables from the Cruciferae family, chronic consumption of poorly detoxified cassava containing large amounts of cyanogenic glucosides, flavonoids, humic substances originating from the organic residues in the soil are clearly involved in the etiology of endemic goiter. Iodine excess, especially in the newborn infants, lithium and thiocyanate overload resulting from smoking habits can be responsible for the development of goiter in non endemic areas.SCOPUS: re.jinfo:eu-repo/semantics/publishe