Platinum-tin bimetallic catalyst on gamma-alumina support was prepared by impregnation method and was reduced by sodium borohydride at room temperature. XRD and XPS characterization revealed that platinum was reduced to Pt-0 while, tin was probably partially reduced to Sn2+ due to the low temperature reduction method and Sn-0 was completely absent, avoiding the formation of P-Sn alloy. Pt-Sn/gamma-alumina (Pt 1%, Sn 9%) thus prepared was found to give almost complete selectivity to gamma-butyrolactone in liquid phase hydrogenation of diethyl succinate. A plausible reaction pathway is proposed involving Pt-O-Sn state and high selectivity to GBL is due to the Lewis acidity of Sn2+/4+ (c) 2006 Elsevier B.V. All rights reserved.