Magnesium oxide (MgO) nanospheres with a high specific surface area were synthesized by the polyol method. The BET specific surface area of the nanopowders was similar to 90 m(2)/g by adjusting the molar ratio of the precursor, the reaction time, and the washing solution. It was increased to 102 m(2)/g by calcining at similar to 250 degrees C. Scanning electron microscopic and transmission electron microscopic observations showed that the MgO nanospheres composed of highly folded flakes, which were responsible for the observed high surface area. The high BET characteristic of the MgO nanospheres can be applied to sintering of microwave ceramics at a reducing sintering temperature, uniformed grain size distribution, and high bulk density. Finally, their capacity to remove hexavalent chromium was presented. (c) 2012 Elsevier Ltd. All rights reserved.