The ordered H-terminated Si nanowire (SiNW) arrays via electroless etching method are capable of reducing silver ions, leading to the deposition of Ag nanoparticles (AgNPs) on SiNW. The AgNPs decorated SiNW arrays are directly fabricated into a novel sensor for the detection of hydrogen peroxide in phosphate buffered solutions. The results of electrochemical experiments reveal that such constructed sensor has a fast amperometric sensing, low detection limit and wide linear responding range as well as high sensitivity. Our results indicate that the AgNPs decorated SiNW arrays with favorable electrocatalytic performance are very promising for the future development of non-enzymatic hydrogen peroxide sensors. (C) 2011 Elsevier Ltd. All rights reserved.