Benzaldehyde hydrogenation over copper catalysts supported on Al2O3, SiO2, TiO2, CeO2 and ZrO2 has been studied at atmospheric pressure and 100-350 degreesC. The reaction competitively produced benzylalcohol, toluene and benzene with yields depending on the nature of the support and reaction temperature. The obtained order of activity was attributed to metal and acid-base surface properties. The important gap in activity (multiplied by 2 to 23) between 300 degreesC and 350 degreesC, observed for all catalysts except Cu/SiO2, was attributed to an adsorption phenomenon, i.e. base sites or low reaction temperature inhibited the reaction course, whereas acidic sites or high reaction temperature enhanced the catalyst activity. Benzylalcohol was obtained with high selectivity (83% at 68% of conversion) from only 100 degreesC with the SiO2 acidic support, whereas selective formation of toluene or benzene was observed at higher reaction temperature and depended on the nature of the support. The relative selectivity of toluene and benzylalcohol was governed by the adsorption strength the alcohol OH function on the catalyst surface. High selectivity to benzene was attributed to the easiness of the catalyst to break the C-H aldehydic bond and stability of the surface organic entity formed. The parallel study of the reduction of benzaldehyde under Nz flow threw some light on the relation between metal and acid-base surface properties of the catalysts and reaction paths in benzaldehyde hydrogenation.