CuO, Cu/Cu2O and Cu2O/CuO nanoparticles (NPs) from a single copper(II) acetate bipyridine complex by three different methods, microwave-assisted, solvothermal and borohydride, are reported. The presence of the bipyridine ligand in the copper complex would impose no necessity for additional stabilization during synthesis. The phases of formed NPs were ident-ified by X-ray diffraction. The CuO NPs obtained via solvothermal synthesis from alkaline solution at 160 °C were of ≈11 nm in size. Cu/Cu2O NPs of≈80 nm were produced via a microwave-assisted polyol procedure at 185–200 °C, where ethylene glycol could play a triple role as a solvent, a reducing agent and a surfactant. Cu2O/CuO NPs of ≈16 nm were synthesized by a borohydride method at room temperature. The interplanar spacing calculated from selected--area electron diffraction data confirmed the formation of Cu, CuO and Cu2O phases in the respective samples. All NPs were stable and could be used for various applications, including biomedicine.