In this study, NaAlH4 has been catalyzed with 10wt% lanthanide oxides such as La2O3, CeO2, Sm2O3 and Gd2O3 by dry ball milling and the hydrogen sorption properties have been investigated. Thermodynamic calculation has also been performed to check the thermodynamic stability of lanthanide oxides in NaAlH4. It is found that NaAlH4 with lanthanide oxides reversibly stores hydrogen and these oxides remain stable in NaAlH4, except CeO2. Sm2O3 shows the best catalytic performance in both the sorption kinetics and cyclic stability among the lanthanide oxides investigated. (c) 2006 International Association for Hydrogen Energy. Published by Elsevier Ltd. All rights reserved.