In the present study, nano-sized ceria (CeO 2 ) powders were prepared using conventional and sonochemically assisted precipitation method, without any stabilizers, using cerium nitrate as a starting material and sodium hydroxide as a precipitating agent. The synthesized ceria powders were characterized by XRD, TGA and SEM to determine crystallite size, % crystallinity, thermal weight loss and shape respectively. It was found that the crystallite size obtained in both the synthesis methods were below 30nm. It was also found that sonochemical synthesis method is energy efficient method saving more than 92% of energy as compared to that utilized by the conventional synthesis method. There was also a significant reduction in the reaction duration.