Abstract: Stabilized nanoparticles of zinc peroxide were formed by a novel and simple technique. The technique is based on oxidation–hydrolysis–precipitation procedure, using zinc acetate as a precursor. The oxidizer was hydrogen peroxide and water was used for hydrolysis and as a preparation medium. The surface modifier was polyethylene glycol 200 (PEG200). ZnO2 was identified and studied by a variety of characterization techniques, including DLS, XRD, DSC, and TEM. Quite stable nanoparticles of ZnO were also obtained from the peroxide powder by heat treatment. The transition temperature, 233°C, was determined by DSC.