This paper, for the first time, demonstrates the three-dimensional imaging of nano-particle infiltrated Ni -GDC (gadolinia-doped ceria) electrodes using focused ion beam tomography. Microstructural parameters of the actual electrode microstructure are quantified, such as volume fraction, TPB density and mean particle/pore sizes. These microstructural parameters reveal that the infiltrated electrodes have eight times larger TPB density than conventional electrodes fabricated by powder mixing and sintering methods. Comparison between the infiltrated electrodes and conventional electrodes indicates that the infiltrated electrodes have a greater potential to independently control metal particle size, porosity and TPB density, which is a significant advantage in developing design optimized electrode microstructures. (C) 2014 Elsevier B.V. All rights reserved.