A mild and convenient synthesis of 1,2,3-triiodoarenes has been developed. This method consists of two steps which can be performed on multigram scale with moderate to excellent yields. This report discloses a practical synthesis of 1,2,3-triiodoarenes and 1,2,3-trihaloarenes that is general in scope, operationally simple, scalable, and is easy to workup and to purify. We also report the first regioselective transmetalation reaction of 1,2,3-triiodoarenes to provide ortho-diiodoaryl derivatives, which are useful building blocks and indeed are hard to make by other means.