The effects of the preparation method (deposition-precipitation, incipient-wetness, combustion) on the structure and redox properties of 1% Au/CeO2 catalyst have been probed by TPR, XRD, and TEM techniques. The catalytic pattern in total (COX) and selective (SCOX) CO oxidation has been assessed by temperature programmed reaction tests in the range 273-473 K. Controlling residual chlorine, the synthesis route determines the strength of the Au-CeO2 interaction which affects both the reduction of the active phase and the CO oxidation functionality. Removal of chlorine by washing in a diluted alkaline solution enables then an easy reduction of Au precursor levelling off the reactivity of the Au/CeO2 catalysts. (C) 2006 Elsevier B.V. All rights reserved.