The fabrication of a conducting polyaniline (PANi) matrix based on a template of polystyrene (PS) latex is of interest from an academic and application viewpoint. In this Full Paper, we propose a distinctly novel strategy, which involves swelling followed by diffusion and polymerization at the interface, to fabricate PANi-coated PS microspheres with uniform size and well-defined shape, regardless of the type of "naked" PS seed particles. Compared to the widely used conventional synthetic protocol, this method affords much more effective control over the structure and morphology of the resultant composites by simply changing the aniline/PS weight ratio or the rate of addition of the doping agent. In addition, it guarantess the easy and successful production of a hollow nanostructure of a conducing polymer with a uniform, intact shell. The synthesized composites have been characterised using Fourier transform infrared spectroscopy, C, H, and N elemental microanalyses, and transmission electron microscopy. The mechanism governing the formation of the composites is discussed.