Siliceous mesostructured microspheres with well-defined pores ranging in size from a few nanometers to over 20 nanometers have been synthesized using evaporative induced self assembly within emulsion droplets. The highly ordered microspheres were templated using a unique combination of amphiphile surfactants and oil microemulsions. The templated nano-structure of the microspheres were characterized by X-ray scattering, nitrogen sorption, and TEM techniques. BET surface areas reported are between 800 and 1000 square meters per gram. Additionally, this technique has been applied to synthesize other inorganic oxide particles, specifically, niobium oxide powders. The open system with pores of varying size and high surface area makes these particles attractive for applications in fuel cell anode templating, drug delivery, and as catalyst supports.