State of the art solid oxide fuel cell (SOFC) anodes are typically Ni based, one of the primary drawbacks of these electrodes is their significant dimensional change upon oxidation. As commercial SOFCs may typically be expected to undergo numerous redox cycles in their operating lifetime, it is important to understand the associated microstructural degradation process. Here we present a methodology for the use of synchrotron based X-ray nano-computed tomography to explore the step-wise oxidation of the Ni phase in a Ni-YSZ composite material. This non-destructive technique demonstrates the potential to track microstructural evolution on a grain-by-grain basis in three dimensions. (C) 2011 Elsevier B.V. All rights reserved.