This work focuses on the effects of Ni precursors (metallic Ni or Mg2NiH4) on the formation of Mg–Fe–Ni intermetallic hydrides as well as their de/rehydrogenation kinetics and reversibility. After ball milling and sintering, the formation of Mg2FeH6and Mg2NiH4are found in both samples, while MgH2is observed only in the sample with metallic Ni. Both samples show comparable hydrogen capacities of 3.2–3.3 wt% H2during the 1stdehydrogenation, but the sample with metallic Ni decomposes at a lower temperature (ΔT= 12 °C) and shows faster kinetics. Although phase compositions after dehydrogenation of both samples are comparable, their rehydrogenation mechanisms are different. This affects the kinetic properties upon cycling and reversibility. Reversible capacities of the samples with metallic Ni and Mg2NiH4during the 2nddehydrogenation are 3.2 and 2.8 wt% H2, respectively, while those during the 3rd–7thcycles reduce to ∼2.8 and 2.6 wt% H2, respectively. Chemical and microstructural characterizations are carried out to explain de/rehydrogenation pathways.