We have synthesized highly oriented mesostructured silica thin films templated with nonionic and cationic mixed surfactant micelles by a solvent evaporation-induced self-assembly process. The mesostructured silica thin films showed constant body-centered cubic lattice structures over a wide range of mixing mote ratios of the cationic surfactant in the nonionic surfactant-rich phase. The degree of ordering of the mixed micellar arrays in the mesostructured silica thin films was enhanced by tuning the mixing mole ratio of the cationic surfactants to nonionic surfactant. (C) 2007 Elsevier B.V. All rights reserved.