In this paper we report studies of the elastic modulus and energy dissipation in lithium amide (LiNH2) during its high temperature decomposition into imide (Li2NH), according to the reaction: 2LiNH(2) -> Li2NH + NH3. The dynamic modulus variations allow the time and temperature evolution of decomposition to be monitored. It is shown that the formation of different phases are detected also at extremely low concentrations. During the amide to imide transformation a considerable increase of the modulus is detected. We found that the reaction rates are remarkably faster than those usually reported. The anelastic spectrum of Li3N presents a strong variation in the elastic modulus, corresponding to the conversion from the beta to the alpha phase. (c) 2008 International Association for Hydrogen Energy. Published by Elsevier Ltd. All rights reserved.