The redox behavior and the structural properties of Ce0.6Zr0.4O2 mixed oxides of high surface area and dense ceramic-type materials are compared. It is shown that due to the insertion of ZrO2 into the CeO2 lattice the oxygen sublattice becomes significantly distorted: Zr-O coordination of the type 5 + 2 and 4 + 2 is found in the former and latter samples, respectively. The nature of these distortions is correlated with the origin of the sample and it appears also to be related to the particle size of the Ce0.6Zr0.4O2 mixed oxide. Noticeably, the reduction behavior of these samples as investigated by the temperature-programmed reduction method appears correlated with their structural properties.