MgAl 2 O 4 spinel was successfully synthesized using a mechanochemical route that avoided the formation and calcination of its precursors at high temperatures. The method involved a single step in which ␥-Al 2 O 3 -MgO, AlO(OH)-MgO, and ␣-Al 2 O 3 -MgO mixtures were milled at room temperature under air atmosphere. The formation of MgAl 2 O 4 occurred faster with ␥-Al 2 O 3 than with AlO(OH) or ␣-Al 2 O 3 . After 140 h, the mechanochemical treatment of the ␥-Al 2 O 3 -MgO mixture yielded 99% of MgAl 2 O 4 .