Indium tin oxide (ITO) films have been prepared by the magnetron sputtering technique from a target of a mixture of In2O3and SnO2in the proportion 9:1 by weight. By optimizing the deposition conditions it has been possible to produce highly transparent (transmission ∼90%) and conducting (resistivity ∼10−5&OHgr; cm) ITO films. A resistivity ∼10−4&OHgr; cm has been obtained for films of thickness ∼1000 A˚ at a comparatively low substrate temperature of 50 °C and without using oxygen in the sputtering chamber. To characterize the films, the following properties have been studied, viz., electrical conductivity, thermoelectric power, Hall effect, optical transmission, and band gap. The effect of annealing in air and vacuum on the properties of the films have also been studied.