Electron-rich 2-methyl and 2-benzylnaphthalenes are efficiently converted into the corresponding carboxaldehyde or ketone by mediated electrolysis in the presence of about 25 mol % of DDQ. The reaction conditions are simple (constant current, undivided cell of 500 ml volume, graphite electrodes, aqueous acetic acid at 80 degreesC) and the construction of a reaction profile (products vs charge) shows the intermediate formation of side-chain acetoxy and hydroxy derivatives and the parallel formation of a byproduct involving side-chain substitution by DDQ.