Polyaniline (PANI)/nano-ZnO composites were prepared by a novel solids-stabilized emulsion (Pickering emulsion) route for the first time. The products were characterized by TEM, XRD, FTIR, SEM, TGA, particle size analyzer and optical microscope. The PANI/nano-ZnO composite particles had polyhedral morphology; they could form hollow spherical structures by assembling at the surfaces of the droplets of the Pickering emulsion; with the increasing of the amount of the ZnO nanoparticles in the reaction mixture, the diameter of the hollow spherical structures decreased; the PANI/nano-ZnO composites had higher thermal stability than pure PANI. A possible mechanism for the formation of the hollow composite structures has been proposed. (C) 2004 Elsevier B.V. All rights reserved.