•Nanostructured copper oxide (II) synthesized by direct sonoelectrochemistry method.•An ultrasonic horn with a copper tip is the anode in the direct sonoelectrochemistry.•Nanostructured copper generated by ultrasound ablation method.•Copper nanostructures converted to nanostructured copper oxide (II) under heating.•The most main advantages of two methods are fast, high purity, and repeatable. In this paper, we present two aspects of the ultrasonic for the synthesis of CuO (II) nanostructures. In the first ultrasound application, we made a copper tip for an ultrasonic probe transducer and used it for electrolysis and ultrasound irradiation processes. This method is named direct sonoelectrochemistry and compares with conventional electrochemistry. CuO (II) nanostructures are obtained after sintering for both direct sonoelectrochemistry method and conventional electrochemistry method. In the second application of ultrasound, the copper nanostructures were generated by the ultrasound ablation method, and then, the heating process was performed for oxidation. The formation of the copper and CuO (II) nanostructures is confirmed by the powder X-ray diffraction (XRD), the field emission electron microscopy (FESEM), and transmission electron microscopy (TEM). The results show that the direct sonoelectrochemistry method generates CuO (II) nanostructures 4.2 times more than conventional electrochemistry. The crystallite size in the electrochemistry methods and direct sonoelectrochemistry is 28.44 nm and 26.60 nm, respectively. The direct sonoelectrochemistry way is a very flexible method and parameters in electrochemical, ultrasound, and the relationship between them can play an important role in the process of synthesis of nanostructures. The crystallite size in the ultrasound ablation method is 21.13 nm and 25.23 nm for the copper and CuO (II) nanostructures. The most important advantages of this method are green, fast, and high purity of the produced nanostructures.