Vanadium oxide (V2O5) and tungsten oxide (WO3) thin films were investigated with the aim to obtain information about their physical and gas sensing properties. The analysis in the presence of different NO concentrations have shown that both materials are able to detect nitrogen oxide, but their responses exhibit different characteristics. In particular, tungsten oxide was found to be more suitable to be used in the field of application for detecting low concentrations. In addition, a mechanism of detection has been considered.