Using a self-shadowing nature, various indium tin oxide (ITO) nanorod arrays were deposited on the surface of GaN-based light emitting diodes (LEDs) by an electron-beam deposition system. The surface morphology and effective refractive index could be controlled by the oblique angle of the deposited ITO nanorod arrays. The surface morphology and the matching refractive index of 1.6 between air and p-GaN layer were obtained for the ITO nanorod arrays with an oblique angle of 45 degrees. Comparing the conventional LEDs without ITO nanorod arrays, the light output power increase of 26.4% is attributed to the surface morphology and the matching refractive index obtained by the ITO nanorod arrays. (C) 2010 The Electrochemical Society. [DOI: 10.1149/1.3436661] All rights reserved.