MgAl2O4 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 gamma-Al2O3-MgO, AlO(OH)-MgO, and alpha-Al2O3-MgO mixtures were milled at room temperature under air atmosphere. The formation of MgAl2O4 occurred faster with gamma-Al2O3 than with AlO(OH) or alpha-Al2O3. After 140 h, the mechanochemical treatment of the gamma-Al2O3-MgO mixture yielded 99% of MgAl2O4.