A nanocrystalline magnesium material with a high specific surface area is expected to react rapidly and reversibly with hydrogen gas to yield magnesium hydride, a hydrogen storage medium. In this paper, the feasibility of the synthesis of magnesium materials for hydrogen storage applications by pulse electrodeposition of magnesium from ethereal electrolytes containing Grignard reagents was investigated. Deposition onto flat stainless steel electrodes established that, as in dc deposition, the morphology of the deposits varied widely with electrolyte composition and charge density. Irregular, nanocrystalline magnesium films were formed at low current density (0.4 mA cm(-2)) and low charge density (1 C cm(-2)) using butylmagnesium chloride electrolytes in dibutyl diglyme, while at a higher current density (15 mA cm(-2)) in tetrahydrofuran, dense films were favored.