Solid state gas sensors have proved to be verypromising for monitoring the emission of airpollutant and toxic gases because they are a low cost element. Titanium dioxide (TiO2) is metal oxide semiconductor.TiO2 has been extensively studied owing to its wide range of applications which include photo catalysis, heterogeneous catalysis, energy storage, solar cell components, corrosion-protective coatings, optical coatings and gas sensing.The objectives of this project was to study the structural, electrical and gas sensing properties of undoped and doped TiO2 thick films.Gas sensing properties of the films werestudied in static gas sensing system by exposing the films to the different gases as CO2, H2S, NH3, Ethanol, LPG and NO2 at different operating temperatures. The optimum operating temperature, sensitivity, selectivity, response, recovery time and the active region of detected gas were determined.Results showed that the doping alters the orientation of microstructure, grain size, composition, electrical and gas sensing characteristics.TiO2 films were observed to be most sensitive to reducing gases than oxidizing gases.