The microstructure and hydrogen sorption behaviour of MgH2 based nano-hydrides with different additives prepared by ball milling and inert gas condensation has been investigated by XRD, Differential Scanning Calorimetry and Mechanical Spectroscopy. Preliminary results on materials with similar composition and different nanostructures show that suitable mechanical processing and additive additions induce in the nanostructured composites tailored channels for improved ab/de-sorption kinetics at reduced temperatures. © 2007 Materials Research Society.