Liquid-phase hydrogenation of cinnamaldehyde over Pt and Ru supported (Y-zeolite, MCM-41) catalysts demonstrated deactivation accompanied by profound decrease of catalysts surface area and by the increase of carbon content. Three consecutive runs with the same catalyst batch typically indicated selectivity increase towards cinnamylalcohol. Changes of activity and selectivity were dependent on the active metal as well as on the support. (C) 2004 Elsevier B.V. All rights reserved.