Highly water dispersible Eu super(3+) doped CaMoO sub(4) nanoparticles (core) covered by CaMoO sub(4) (shell) have been prepared using the polyol method. Significant enhancement in luminescence intensity by coreatshell formation is observed due to the decrease of non-radiative rate arising from surface/defect of particles. Effect of 266 nm laser excitation (Mo-O charge transfer band) on the asymmetric ratio (A sub(21) = intensity ratio of electric to magnetic dipole transitions) has been studied and compared with a xenon lamp source. Luminescence intensity increases with the increase of power at 532 nm laser excitation. In order to explore materials, which can show dual functionalities such as luminescence as well as magnetic properties (magnetization of similar to 14.2 emu g super(-1)), water dispersible Fe sub(3)O sub(4)-CaMoO sub(4):Eu hybrid magnetic nanoparticles (MN) have been prepared. This shows good heating ability up to similar to 42 degree C (hyperthermia) and luminescence in the red region ( similar to 612 nm), which is in a biological window (optical imaging). Biocompatibility of the synthesized Fe sub(3)O sub(4)-CaMoO sub(4):Eu hybrid magnetic nanoparticles has been evaluated in vitroby assessing their cytotoxicity on human liver cancer cells (HepG2 cells) and hTERT cells using the MTT assay and fluorescent microscopy studies.