Surfactants have been shown to organize silica into a variety of mesoporous forms, through the mediation of electrostatic, hydrogen-bonding, covalent and van der Waals interactions(1-8). This approach to mesostructured materials has been extended, with sporadic success, to non-silica oxides(5-17), which might promise applications involving electron transfer or magnetic interactions. Here we report a simple and versatile procedure for the synthesis of thermally stable, ordered, large-pore (up to 140 Angstrom) mesoporous metal oxides, including TiO2, ZrO2, Al2O3, Nb2O5, Ta2O5, WO3, HfO2, SnO2, and mixed oxides SiAlO3.5, SiTiO4, ZrTiO4, Al2TiO5 and ZrW2O8. We used amphiphilic poly(alkylene oxide) block copolymers as structure-directing agents in non-aqueous solutions for organizing the network-forming metal-oxide species, for which inorganic salts serve as precursors. Whereas the pore walls of surfactant-templated mesoporous silica(1) are amorphous, our mesoporous oxides contain nanocrystalline domains within relatively thick amorphous walls. We believe that these materials are formed through a mechanism that combines block copolymer self-assembly with complexation of the inorganic species.