Herein, we describe a solvent- and metal-free method for the synthesis of 3-chalcogenyl-indoles from indoles and diorganyl dichalcogenides using an equivalent amount of DMSO as an oxidant, under catalysis by molecular iodine. This mild and eco-friendly approach allowed the preparation of a wide range of 3-selenyl- and 3-sulfenyl-indoles in good to excellent yields.