The deposition of indium zinc oxide (IZO) thin films was carried out on glass substrate at room temperature by dc magnetron sputtering. The effects of dc power and deposition pressure were investigated with respect to physical and optical properties of films such as deposition rate, electrical properties, microstructure and transmittance. As the dc power increases, the resistivity slightly increases and the transmittance gradually decreases. For the variation of deposition pressure, the resistivity greatly increases and the transmittance is decreased with increasing deposition pressure. The observation of the IZO films by atomic force microscopy indicates that the microstructure and surface morphology of the films are responsible for the transmittance. It was demonstrated that IZO films with a resistivity of 3.8 x 10(-4) Omega cm and an optical transmission of 80-90% in the visible spectrum could be prepared without post deposition annealing. (C) 2004 Elsevier B.V. All rights reserved.