In2O3 octahedrons have been synthesized by heating InCl3 aqueous solution on the Si substrate at 400-900 degrees C for 2 h. The average size of In2O3 Octahedrons is decreased by increasing the heating temperature. The In2O3 octahedrons are single-crystalline with the body-centered Cubic structure and have controllable sizes in the range of 0.7-1.0 mu m. A possible mechanism was also proposed to account for the formation of In2O3 octahedrons. A strong photoluminescence with a peak at 458 non was observed from the In2O3 octahedrons at room temperature. This emission can be attributed to oxygen vacancies and indium-oxygen vacancy centers. (C) 2008 Elsevier Ltd. All rights reserved.