We introduced a method for polyol synthesis of Cu-NPs in ethylene glycol (EG). This simple method takes place across the slow reduction of copper ions from copper nitrate and copper sulfate in ethylene glycol in the presence of a polymer surfactant (Polyvinylpyrrolidone: PVP), which was added to preclude agglomeration and provide dispersion stability to the final colloidal nanoparticles. Additionally, a double-salt reduction method enabled high-quality uniform nanoparticles to be obtained. The uniform size of the spherical copper nanoparticles could be controlled within the range of 10-55 nm by varying the synthesis parameters. Additional reducing agents were used to decrease reaction time, but these implantations had effects on the size and shape of the nanoparticles. Copper NPs mostly have a single crystal morphology. We also present an easy way to produce Cu-CuO NPs which can be used in different applications.