Production of nanosized oxides was reliably accomplished through magnetron radio frequency sputtering of a W/Ti composite target under oxidizing environment. Depending on the temperature at which annealing was carried out, the resulting thin films were either WO3/TiO or W-doped TiO and the semiconductor doping changed from n to p type, respectively. The films were structurally characterized through microscopy techniques. Electrical characterization was executed over the samples. In particular, it was observed that the films responded with high sensitivity to NO2, a gas of increasing importance in environmental monitoring. We describe the features of the sensing layers with particular focus on the role of TiO-this p-type material being a novelty for the field of gas sensing.