Magnesium-nickel alloys with nickel concentrations from 0 to 60 at % were prepared by three methods : inert gas condensation of sputtered nanocrystalline powder, cosputtering of amorphous thin films and ball milling. Of the three methods, ball milling yields the best hydrogen storage properties in terms of hydrogen capacity, hydriding/dehydriding rates, and activation requirements. In addition, these characteristics are achieved in magnesium with only very small nickel concentrations, on the order of a few atomic per cent.