Ag/Zr0.9Ni0.1Oy nanocomposites with different atomic ratios of Ag to Zr0.9Ni0.1Oy (Ag/Zr0.9Ni0.1Oy = x where ‘‘x” is 0%, 5%, and 20%) were synthesized through co-precipitation technique. The structure and morphology properties of the Zr0.9Ni0.1Oy nanocomposites were evaluated by X-ray diffraction (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS) techniques. The permittivity and permeability behaviors of samples were investigated. Results showed that when 20 wt.% Ag was added (named S20), the permittivity and the permeability of the S20 became negative. These results imply the realization of double negative properties in S20 as a desired candidate for the double negative materials (DNMs).