A non-invasive electromagnetically enhanced oil recovery (EOR) method by injecting nanofluids into the oil reservoir simultaneously with electromagnetic irradiation, with the intention to create disturbance at oil-water interfaces and increase oil production has been proposed. Dielectric nanoparticles having relatively high dielectric loss factor were chosen due to the abundance of bound surface charges which exist at the surface. In this research, zinc oxide, ZnO and aluminium oxide, Al2O3 nanoparticles were successfully synthesized by sol-gel method. Zinc nitrate hexahydrate and aluminium nitrate nonahydrate were used as the precursors for ZnO and Al2O3 respectively. Solutions formed by dissolving zinc nitrate hexahydrate and aluminium nitrate nonahydrate in nitric acid were stirred in 14 days to ensure homogeneity. The resulting xerogels were annealed at various temperatures; 200°C, 250°C and 300°C for ZnO and 900°C, 1000°C and 1100°C for Al2O3, respectively. The as-synthesized ZnO and Al2O3 nanoparticles were characterized by X-Ray Diffraction (XRD), Field Emission Scanning Electron Microscope and Energy Dispersive X-Ray Spectroscopy (EDX). XRD analysis shows that the resulting nanoparticles have high crystallinity, which can be indexed to standard hexagonal structure for both ZnO and Al2O3, having average crystallite size of 45nm and 38nm, respectively. Dielectric properties of both nanoparticles shows that Al2O3 has higher dielectric losses in the low frequency region compared to ZnO which may be resulted from its highly porous structure and impurities existence. © 2012 American Institute of Physics.