The Mm, Ti-substituted Zr(1-2x)Mm(x)Ti(x)Fe(1.4)Cr(0.6) (x = 0, 0.05, 0.1 and 0.2) Laves phase alloys show high hydrogen storage capacity of similar to1.75 wt% and kinetics of similar to 30 cm(3) min(-1) g(-1) which is 3 times faster than the parent alloy ZrFe1.4Cr0.6. High hydrogen storage capacity is observed for small concentrations of Mm (x = 0.03-0.07). The best storage materials correspond to the composition of x = 0.05. Eventhough the Mm-substituted Laves phase alloys Zr(1-x)Mm(x)Cr(1.4)Cr(0.6) (x = 0, 0.05, 0.1 and 0.2) have high capacity of 1.6 wt%, their kinetics is rather poor (< 10 cm(3) min(-1) g(-1)). The high hydrogen storage capacity and fast kinetics of Mm, Ti-substituted alloys are attributed to disorder/defects introduced as evidenced through XRD, SEM and TEM studies. (C) 2001 Published by Elsevier Science Ltd on behalf of the International Association for Hydrogen Energy.