Near-monosized and uniformly distributed cubic Fe core-shell nanoparticles (with an average side length of 56 nm) were electrodeposited on H-terminated Si (100) in a FeCl2 solution. X-ray photoelectron spectroscopy analysis indicates chemical states of the Fe nanocubes characteristic of predominant ferromagnetic metallic Fe cores covered by Fe2O3 shells. Glancing-incidence X-ray diffraction analysis reveals a body-centered cubic (bcc) lattice structure. A nanometer-thick film consisting of 2-3 layers of cuboidal nanoparticles of the same bcc Fe core and Fe2O3 shell can be obtained when the amount of charge transfer is increased. The prominent magnetic domains of these nanocubes can be illustrated by magnetic force microscopy. (c) 2007 The Electrochemical Society.