Yttrium oxide nanoparticles (Y 2 O 3 ) have been synthesized by a low temperature co-precipitation method. The precursor material used in this research was yttrium nitrate hexahydrate (as a basic material), ammonium hydroxide (as a precipitating agent) without surfactant. The resultant precipitate Y(OH) 3 was washed with deionized water several times and then heat treated at 450 °C for 1hr. The prepared Y 2 O 3 nanoparticles were characterized by TG-DTA, XRD, DLS, Zetasizer and TEM. From the results obtained, Y 2 O 3 ultrafine nanoparticles with particle size of 7.78 nm were successfully prepared as promise for wide range of applications.