The decolorization of Acid Red 1 (AR1) in aqueous solution was investigated by Fenton-like process. The effect of different reaction parameters such as different iron ions loading on rice husk ash (RHA), dosage of catalyst, initial pH, the initial hydrogen peroxide concentration ([H2O2](o)), the initial concentration of AR1 ([AR1](o))and the reaction temperature on the decolorization of AR1 was studied. The optimal reacting conditions were found to be 0.070 wt.% of iron (III) oxide loading on RHA, dosage of catalyst = 5.0g L-1, initial pH = 2.0, [H2O2](o) = 8mM, [AR1](o) = 50mg L-1 at temperature 30 degrees C. Under optimal condition. 96% decolorization efficiency of AR1 was achieved within 120 min of reaction. (C) 2009 Elsevier B.V. All rights reserved.