A new electrophilic selenocyanation reagent, selenocyano-benziodoxolone, was successfully prepared from 2-iodobenzoic acid in two steps (71% overall yield). A variety of α-selenocyanated ketones and β-ketoesters, including selenocyanate-containing steroid derivatives, have been achieved by using this newly developed selenocyano-benziodoxolone in good to excellent yields (up to 99%) simply by grinding under mild conditions.