Nitrosonium cations generated by the one-electron oxidation of nitroxyl radicals are known to serve as selective oxidizing agents for alcohols to aldehydes or ketones, We prepared glassy carbon rotating disk electrodes (RDE) modified with 2,2,6,6-tetramethyl-piperidinyl-1-oxyl (TEMPO) via a very thin layer of poly(acrylic acid) and studied the electrode processes of 4-methoxybenzyl alcohol oxidation taking place at the modified electrodes in acetonitrile solution containing 0.2 mol dm(-3) sodium perchlorate using cyclic voltammetry and RDE voltammetry. It was found that though the presence of a base such as 2,6-lutidine is essential for the alcohol oxidation to proceed at a reasonable rate, the limiting current values corresponding to the rate of the alcohol oxidation at the RDE scarcely depend on the lutidine concentration. On the basis of these findings and electrochemical characteristics of TEMPO modified electrodes, we considered three possible reaction mechanisms and derived corresponding equations which relate the limiting current to rotation frequency of the RDE and concentrations of the alcohol and the base. We analyzed the experimental data by using the derived equations and proposed as the roost probable reaction mechanism the one giving the most reasonable kinetic parameters and in which the rate-determining step is the decomposition of an intermediate formed from the nitrosonium cation, the alcohol and the base.