The hydriding behavior of the Mg17Al12 intermetallic compound was studied in detail. It was found that the Mg17Al12 compound can initially react with hydrogen to form Mg2Al3, MgH2 and Al at 573 K. Increasing the hydrogenation temperature to 623 K, further hydriding leads to the decomposition Of Mg2Al3 into the hydride MgH2 and the Al-based solid solution Al0.9Mg0.1..,. (c) 2005 Elsevier B.V. All rights reserved.