A set of catalysts comprised of gold on different CeO2 supports has been prepared by a nanocasting route and characterized by several physicochemical techniques. These catalysts have been tested for CO oxidation and show outstanding catalytic activity. Higher calcination temperatures of the hard template, producing a poorly ordered silica template, have led to a higher amount of oxygen vacancies on the surface of CeO2. The presence of surface oxygen defects in the support combined with the deposition of Au nanoparticles (ca. 3 nm) homogeneously dispersed on the CeO2 support may explain the excellent behaviour for low temperature CO oxidation. Surprisingly, it has been observed that the degree of inverse replication of the template is not relevant in the catalytic performance, as in all cases neither the characteristics of the ceria surface nor the dispersion and oxidation state of gold are greatly modified by the formation of inter-particle bridges. (C) 2014 Elsevier Inc. All rights reserved.