Abstract The Meerwein—Pondorff—Verley (MPV) reaction between ethanol and acetone was investigated on various metal oxides having different acid-base properties. It is shown that the reaction occurred on Lewis acid or base catalysts. From results of specific poisoning and FTIR studies of ethanol and acetone or acetone ( d 6) adsorption, two different schemes are proposed for the MPV reaction, according to the metal oxide's presented surface basicity (MgO, ZrO 2) or Lewis acidity (Al 2O 37z.sbnd;Cl). On amphoteric catalysts (Al 2O 3) both schemes were possible. Secondary reactions, which mainly occurred on acidic catalysts as condensation of acetone and/or acetaldehyde and alcohol dehydration, are also discussed.