A combination of medium energy ion scattering (MEIS), grazing incidence small angle X-ray scattering and transmission electron microscopy techniques was used to investigate a planar set of Pb nanoparticles (NPs) located at the SiO2/Si interface synthesized by ion implantation, and the bimodal NPs' shape nature of this system was revealed. The present results help to improve the understanding of the use of MEIS on the investigation of the microstructural and morphological properties of buried nanostructured systems and show the importance of the combination with appropriate complementary techniques. (C) 2014 Elsevier B.V. All rights reserved.