The main goals of this study are to synthesize a mixed metal oxide nanocomposite (NC), CdO-CuO-Co3O4, and to analyze its structural, morphological, optical, and electrical properties using X-ray diffraction (XRD), total reflection X-ray fluorescence (TXRF), transmission electron microscopy (TEM), diffuse reflectance spectroscopy (DRS), and DC electrical resistivity. According to the XRD analysis, CuO nanoparticles (NPs) have a monoclinic structure, while CdO and Co3O4 (NPs) have cubic structures. The TEM images revealed a decrease in the particle size of CdO-CuO-Co3O4 (NC) compared with that of the NPs. The optical properties of CdO-CuO- Co3O4 (NC) were examined using a DRS in the wavelength range of 400-700 nm. The DC electrical resistivity results showed the semiconducting electrical behaviors of the samples.