Sub-micron sized hollow spheres were fabricated starting from core-shell particles. Polystyrene particles with a size of 345 nm were coated with a titania shell of 15 nm thickness by a sol-gel method. The core-shell particles prepared were annealed at 500degreesC in air to remove the polystyrene core and crystallize the titania shell. The crystal structure of the hollow titania shell was anatase and its surface area was 91.0 m(2)/g.