In the present work, cold rolling has been investigated as a new means of producing Mg-based metal hydrides for nickel–metal hydride (Ni–MH) batteries. Structure and electrochemical evolution of 2Mg–Ni cold-rolled samples were investigated as a function of the number of rolling passes as well as heat treatment. It was found that nanocrystalline Mg2Ni alloy can be obtained by an appropriate three step process involving rolling, heat treatment and rolling again. It was shown that the number of primary and secondary rolling passes must be carefully optimized in order to favour the complete formation of Mg2Ni alloy having a nanocrystalline structure (∼10nm in crystallite size) without excessive sample oxidation. Actually, the best result was obtained by first rolling 90 times, followed by a heat treatment at 400°C for 4h and roll again 20 times. The resulting material displayed an initial discharge capacity of 205mAhg−1, which is quite similar to that obtained with ball-milled Mg2Ni alloy.