A study has been made on the iodination of phenols by elemental iodine in Na2CO3 solution. The results attained by applying the suggested procedure to a number of practical cases have been very encouraging. This method gives rise to the iodine derivatives of aldehydes (2-hydroxy- and 4-hydroxy-3,5-diiodobenzaldehyd), ketones (2-hydroxy-5-iodo-, 2-hydroxy-3,5-diiodo- and 4-hydroxy-3,5-diiodo-acetophenone, 4-hydroxy-3,5-diiodo-propiophenone), acids (3,5-diiodo-4-hydroxybenzoic acid, 3-formyl-4-hydroxy-5-iodobenzoic acid), aminoacids (3-iodo- and 3,5-diiodo-tyrosine), esters (methyl ester of 2-hydroxy- and 4-hydroxy-3,5-diiodobenzoic acid, methyl ester of 3-iodo-5-chloro-, 3-iodo-5-bromo- and 3,4,5-triiodosalicylic acid, dimethyl- and diethyl-ester of 4-hydroxy-5-iodo-isophthalic acid), amides (2-hydroxy-3,5-diiodobenzamide) and benzoxazole derivatives (2-(2'-hydroxy-3',5'-diiodophenyl)benzoxazole).