A strategy to prepare stable monodispersed fluorescent microspheres is developed by modifying the Wessling method to synthesize poly(p-phenylenevinylene) (PPV) on the surface of a highly crosslinked polymer core. The positively charged PPV polymer precursors (pre-PPV) are adsorbed onto the core with negative charges on the surface and then the insoluble fluorescent PPVs form after thermal elimination. Each individual sphere is found to possess a very smooth surface with an even distribution of fluorescence by microscopic techniques. Very small coefficient of variance (CV) values of emission intensity (<4.0%) and size (<2.3%) are realized for microspheres prepared in the same batch. The spheres are demonstrated to have good thermal stability and photostability.