Ag/TiO2 photocatalytic films were produced by hybrid sol–gel method. The photocatalytic degradation of methyl orange (MO) in aqueous solution under 365 nm irradiation on TiO2 and Ag/TiO2 thin films was investigated. The state and amount of Ag species within the film and the enhancement mechanism of photocatalytic activity of Ag/TiO2 were discussed. With a loading molar ratio of Ag/Ti = 0.135 in TiO2 film, the maximum catalytic efficiency was observed.