Electrochemical oxidation of arylmethylselenides in acetonitrile in the presence of a strong proton donor follows an E + C2 scheme contrariwise to E + C1 + E scheme for the oxidation of alkylarylselenides under non-protic conditions, The reaction constants of first and second order potential determining reactions of electrogenerated cation radicals have different signs which, given the electron transfer reaction constant being the same in both cases, determines different sensitivity of the apparent oxidation potential E-1/2 towards the ring substitution.