In this Letter, nanostructured materials consisting of cobalt nanoparticles and different matrixes and formed by universal thermal destruction method are presented. Ultradispersed polytetrafluoroethylene (UPTFE) and polyethylene were used as matrixes for surface or volume stabilization of nanoparticles. ⁵⁹Co NMR and X-ray diffraction methods were used to determine the structure of cobalt nanoparticles. The NMR data confirmed mainly the presence of hcp-like crystalline structure.