This article presents a facile method to prepare silver/polystyrene composite microspheres. In this approach, monodispersed polystyrene (PS) particles were synthesized with carboxyl acid groups on the surfaces of the PS particles via dispersion polymerization at first. With the addition of [Ag(NH3)(2)](+) to the PS dispersion, [Ag(NH3)(2)](+) was absorbed to the surfaces of the PS particles, and then by heating the system, [Ag(NH3)(2)](+) complex ions were reduced to silver to form the Ag/PS composite microspheres. In the synthesis of PS dispersion, PVP was used as dispersant to stabilize the PS particles, it also acted as reducing agent in the reduction of [Ag(NH3)(2)](+) complex ions to silver, so no additional reducing agent was needed. The resulting composite microspheres were characterized by TEM, SEM, XPS, and XRD. The catalytic properties and surface-enhance Raman scattering (SERS) was studied as well. (C) 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 4547-4554, 2009