Complex chemical hydrides can be used to store and deliver hydrogen gas to fuel cells, and thus are one of several candidate materials to be used in storage systems for the hydrogen economy. These hydrides have high native hydrogen content, and hydrogen can be released via several chemical pathways. This review summarizes the extensive literature on the kinetic and thermodynamic properties of the various reactions of chemical hydrides, with an emphasis on hydrolysis. These properties are significant because they affect all aspects of system design, as well as the recovery and recycle of the byproducts. Hydrolysis of chemical hydrides takes place at relatively low temperatures and gives promising theoretical hydrogen storage efficiencies. Complications include metastable kinetic pathways as well as inefficient utilization of water in the byproducts.