We have developed a mild and practical synthesis of primary, secondary and tertiary alkyl iodides by iododecarboxylation (decarboxylative iodination) of the corresponding carboxylic acids using (diacetoxyiodo)benzene and iodoform under ambient conditions. The method does not require heating or intense light irradiation and can be used to install iodine at the bridgehead position of strained cycloalkanes, as well as in a variety of alkanes with complex frameworks/functionalities.