Novel mesoporous FeAl bimetal oxides with large surface area were synthesized. FeAl bimetal oxides performed much better than their single metal oxides. Over 99% of As(III) was removed in 90 min at pH 3.0–11.0 by FeAl bimetal oxides. As(III) was removed by its complexation with surface OH of FeAl bimetal oxides.