Indium tin oxide (ITO) films were deposited onto the glass substrates at different substrate temperatures (RT-500 degrees C) by rf reactive magnetron sputtering method. The structural, optical and electrical properties of ITO films have been characterized by X-ray diffraction, scanning electron microscopy, optical transmittance and reflectance, sheet resistance and electrical resistivity measurements. The films deposited at low substrate temperature have a very strong (222) diffraction peak which means a preferred orientation along the [111] direction. As the temperature is increased, the (400) diffraction peak intensity increases and results in a preferred orientation along [100] direction for the films prepared at 500 degrees C substrate temperature. The film prepared at 400 degrees C substrate temperature has the lowest electrical resistivity (about 3.7 X 10(-4) Ohm cm).