Zinc peroxide (ZnO2) nanopowder is a potential green precursor to obtain ZnO nanostructures at low temperatures. Here, it is reported the synthesis of ZnO2 nanoparticles through an economical one step hydrothermal method. The thermal stability, morphology, structural and vibrational properties of the ZnO2 nanoparticles were studied by means of thermogravimetry/differential scanning calorimetry. X-ray diffraction, low- and high-resolution transmission electron microscopy, infrared spectroscopy and Raman spectroscopy. Highly crystalline cubic-ZnO2 nanoparticles with average size of 15 nm were obtained. It was found that the synthesized ZnO2 sample decomposes into ZnO at about 250 degrees C. The observed vibrational modes in the ZnO2 nanopowder are discussed and compared with previous reports. (C) 2010 Elsevier B.V. All rights reserved.