The oxygen self-diffusion in partially reduced CeO2 has been investigated by large-scale Molecular Dynamics simulations, in the temperature range between 800 and 2200 K. Simulation boxes with similar to 4100 and similar to 33,000 ions were investigated for randomly distributed oxygen vacancies and Ce3+ ions. Our calculated self-diffusion coefficients vary between 10(-8) and 10(-6) cm(2)/s in the temperature range studied. The activation energy and D-0 values are also reported. The oxygen diffusion mechanism has also been analyzed: only a (< 100 > vacancy mechanism is observed. (c) 2007 Elsevier B.V. All rights reserved.