(MgH2 + Y, Ce) mixtures were processed by mechanical milling in an attempt to improve the hydrogen sorption properties of MgH2. The structural evolution and hydrogen desorption properties were investigated by a range of experimental techniques. XRD analysis shows the formation of a stable hydride phase, CeH2.35 or YH3, in the relevant mixture during milling. Hydrogen desorption of the milled mixtures was characterised by coupled thermogravimetry (TG) and differential scanning calorimetry (DSC). Milled (MgH2 + Ce) samples show higher desorption kinetics than the (MgH2 + Y). The formation of CeO2 in the (MgH2 + Cc) mixture benefits the desorption kinetics, likely due to the formation of surface defects on MgH2 and surface catalysis by the oxide. (c) 2006 International Association for Hydrogen Energy. Published by Elsevier Ltd. All rights reserved.