Herein polypyrrole-polystyrene (PPy-PS) hybrid hollow spheres have been prepared by a facile method. In the synthesis, pyrrole was oxidatively polymerized by FeCl3 center dot 6H(2)O in an emulsion of PS latex. The produced PPy deposited onto the surface of the PS particles, which were "dissolved" during the polymerization for the in-situ formation of hollow PPy spheres. The morphology of the hollow spheres was characterized by transmission electron microscope (TEM) and scanning electron microscopy (SEM). The size and size distribution of the hollow spheres were totally depended on that of the PS latex particles which can be adjusted conveniently. The PPy-PS hybrid structure of the shell of the hollow spheres was characterized by selective extraction using tetrahydrofuran (THF) and Fourier transform infrared (FTIR) spectroscopy. The formation process of the hollow spheres was traced by TEM. The probable mechanism for the formation of hollow spheres was also proposed in this work. The influences of the reaction conditions on the formation of the hollow structures have been studied in detail. (c) 2012 Elsevier B.V. All rights reserved.