An unprecedented silver-mediated vicinal trifluoromethylation-iodination of arynes that quickly introduces CF3 and I groups onto aromatic rings in a single step to give o-trifluoromethyl iodoarenes has been developed. A new reactivity of AgCF3 has been revealed, and 2,2,6,6-tetramethylpiperidine plays an important role in this difunctionalization reaction.