A facile method is disclosed for the synthesis of α-thio/selenocyanato ketones through regioselective C–H thio/selenocyanation of ketones. The advantages include the use of easily available starting materials, high efficiency, simple operation, and easy scale-up. Control experiments provide evidence that the reaction proceeded via a radical way, while kinetic isotope effect experiments reveal that the cleavage of the C–H bond serves as the rate-limiting step.