We report the dielectric constant, Young's elastic modulus, and hardness of disordered mesoporous silica films prepared by spin-coating a silica precursor and nonionic triblock copolymer surfactant templates. The effects of selection of surfactant molecule on the properties of mesoporous silica films with disordered pore structures were investigated. One of the disordered mesoporous silica films studied had a low dielectric constant k = 2.0 and a high mechanical strength of elastic modulus = 4.14 GPa and hardness = 0.4 GPa. It has been shown that the modulus and hardness of the disordered mesoporous films can be made as high as those of two-dimentional hexagonal ordered mesoporous films. (C) 2004 The Electrochemical Society.