All-nanoparticle multilayer films were prepared by layer-by-layer deposition of SiO2 and Al2O3 nanoparticles onto polyester (PE) substrate. The top-most SiO2 (and Al2O3) layer was characterized using ToF-SIMS and SEM. An element-specific homogeneity index obtained by ToF-SIMS measurement provides clue to the formation mechanism. Experimental results from ToF-SIMS and SEM accord well with molecular dynamics simulation results, demonstrating the potential of using ToF-SIMS to study all-nanoparticle multilayer films. (C) 2008 Elsevier B. V. All rights reserved.