Copper (II) Oxide (CuO) nanoparticles can be synthesized by many different methods. Among them, the chemical precipitation method and pulsed laser ablation technique were applied according to the simplicity of the methods and the effectiveness of the cost and the product. For the former method, by using copper sulfate pentahydrate is a precursor and ammonia solution as a stabilizing agent, CuO nanoparticles were produced. For the latter method, the pure copper target metal (immersed in the liquid environment of distilled water) was ablaze by using 1064 nm wavelength of Neodymium: Yttrium Alumina Garnet (Nd: YAG) laser for producing CuO nanoparticles. The synthesized CuO nanoparticles were characterized by XRD, SEM, FTIR, and Zetasizer (DLS). X-ray Diffraction (XRD) pattern confirmed that as-synthesized particles were CuO and Fourier Transform Infrared Spectroscopy (FTIR) was used to study the vibrational frequencies between the bonds of atoms for a synthesis CuO nanoparticles. The Scanning Electron Microscope (SEM) analysis indicated flake-like and spherelike structures for chemical precipitation and pulsed laser ablation techniques. The zetasizer was used to study the size distribution of the CuO nanoparticles.