The present study aims to produce and characterize magnetic iron oxide spheres on a micro - and nanoscale. Based on the process of spheroidization by flame, an industrial ferruginous laterite was used as a precursor. The micro- and nanospheres produced were magnetically separated and classified. The composition, microstructure and magnetic behavior of iron-based micro- and nanospheres were characterized by XRD, SEM, TEM and Mössbauer spectroscopy. Results showed interesting differences in terms of crystallinity for iron oxides samples, e.g. hematite, goethite, and magnetite could be identified (polycrystalline samples). Microscopy characterization gave a valuable evidence of shape homogeneity, polydispersity (microspheres up to 100 μm and nanospheres around 6 nm) and dendritic surface morphology of the particles. Magnetite dominated in iron oxide powder samples. In addition, the magnetization curves corresponded to assemblies of individual magnetic particles with mutual dipolar interactions.