A new access to copper(0) nanoparticles (CuNPs) from readily available organocopper reagents is reported. This original amine-free methodology proves to be practical, fast and highly reproducible. It yields spherical CuNPs with an excellent control of their size and shape. These CuNPs are fully characterized by electronic microscopy (TEM, HRTEM), X-Ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), and UV-Vis spectroscopy. The size of the synthesized nanoparticles is in a size range of 5-9 nm. The reactional pathway is studied and shows a two-step process implying the formation of a primitive bulk composed of spheroid CuNPs followed by a reorganization step induced by a thiol additive and leading to the final NPs.