Monodispersed nanoparticles of Ag(I)–polymer hybrids have been prepared by using designed crown-ether-centred two-armed copolymers to chelate Ag⁺ ions at the interface of organic–aqueous solutions. The copolymer–Ag⁺ complex nanoparticles, as well as the reduced copolymer–Ag nanoparticles, have been characterized by transmission electron microscopy (TEM), atomic force microscopy (AFM), and x-ray photoelectron spectroscopy (XPS). The particle size can be varied by simply changing the polymer concentration, the monomers, and/or the molecular weight. The copolymer–Ag(I) hybrids exhibit weak photoluminescence, which was substantially enhanced after the hybrids were reduced to copolymer–silver nanoparticles with UV irradiation.