Recent advances in chemical hydrogen storage systems are reviewed. Factors impacting design and implementation of chemical hydrogen storage systems for on-board vehicular use are highlighted. The physical and chemical characteristics of chemical hydrogen fuels and their spent fuel counterparts are considered to provide guidance to future technology developers. Heat management, fuel stability, reactor design, and fuel morphology are examples of issues that must be considered for the future of chemical hydrogen storage systems. (C) 2009 Published by Elsevier Ltd on behalf of International Association for Hydrogen Energy.