In memory of KevinThe first iodine(III)-mediated para-selective iodination protocol for free anilines as well as the mechanistic elucidation of the reaction pathway is described. The developed method proceeded under clean, non-toxic, efficient, and in general mild reaction conditions. To the best of our knowledge this report describes for the first time a procedure focused specifically on the introduction of an iodine atom in free anilines using PIDA [(diacetoxyiodo)benzene] and ammonium iodide which formed in situ acetyl hypoiodite (AcO-I) as the halogenating species. Our DFT calculations suggest a reaction mechanism that highlights the catalytic role of the ammonium cation in the AcO-I formation and halogenation. Considering there are few procedures for the iodine atom introduction in anilines using non-acidic conditions, herein we described an initial report on a mild and operationally simple alternative using iodine(III) reagents.