A room temperature solution process for synthesis of Fe3O4 nanoparticles and their hybrid core shell nanostructures using CdS as the shell material has been described. The as grown particles have been characterised using XRD. Rietveld refinement, high resolution transmission electron microscopy, atomic force microscopy, superconducting quantum interference device, optical absorbance and photoluminescence spectroscopy. A superparamagnetic response revealed from the magnetisation measurements of the as synthesised magnetite nanoparticles was retained even after the growth of the CdS shell. From luminescence and high resolution atomic force microscopy measurements, it is shown that the core shell structures advantageously combine magnetic as well as fluorescence response with a tendency towards self-organization. (C) 2012 Elsevier Ltd. All rights reserved.