In this work, the decolorization of Acid Red 1 (AR1) by Fe (III) oxide-kaolin catalyst was studied. The effects of iron (III) oxide loading on kaolin, catalyst dosage, pH and initial concentration of hydrogen peroxide (H2O2) on decolorization of AR1 were studied. The best catalytic results showed that at a reaction temperature of 30 degrees C, pH 3.0, 8.0 mM of H2O2 and 4.0 g/L of 0.080 wt.% Fe-kaolin, 98.46% decolorization was achieved within 240 min treatment. It was also observed that catalytic behaviour could be reproduced in consecutive experiments with low iron leaching. (C) 2010 Elsevier B.V. All rights reserved.