Organic-inorganic hybrid hollow spheres are prepared by using a TiO2-stabilized Pickering emulsion polymerization method (see figure). By self-organization of TiO2 nanoparticles at the interface of oil (monomer and solvent) and water, colloidosomes are formed and used as polymerization vessels to obtain the hybrid hollow spheres. The diameter and mechanical stability can be tailored by varying the relative amount of oil phase and the relative amount of divinylbenzene (DVB) in the monomer, respectively.