Nanoparticles of cerium tungstate have been prepared in the nanodomain water pools of water/AOT [sodium bis(2-ethylhexyl)sulphosuccinate]/n-heptane, water in oil microemulsion at various [water]/[AOT] mole ratio (omega) by double displacement reaction of cerium nitrate with sodium tungstate adapting intermixing two microemulsions technique. The formation of cerium tungstate in the dispersion has been established by UV vis, X-ray diffraction and Fourier transform infrared measurements. Thermal stability of the products has been determined by thermogravimetric/differential thermal analyzer. The hydrodynamic diameter of the nanoparticles formed at different omega has been determined by the dynamic light scattering method. The size and shape of the isolated particles have been examined by the transmission electron microscope. Size of the nanoparticles increases with increase in omega. The fluorescent property and the magnetic behaviour of the synthesized product have been observed. The nanoparticles do not undergo any chemical change in HCI medium but unstable in KOH. (C) 2010 Elsevier B.V. All rights reserved.