Highly conductive indium tin oxide (ITO) films were deposited by r.f. magnetron sputtering using ITO targets. The composition of the ITO targets was 90% indium oxide and 10% tin oxide. ITO films were deposited on 1 mm thick soda lime glass. Films deposited at substrate temperature of 300 degrees C, exhibited resistivities as low as 1.3 x 10(-4) ohm cm(-1). Annealing of the ITO films in air for 2 h was necessary for achieving low resistivities. X-ray diffraction and transmissivity tests were carried out to study the effects of annealing. Lowest resistivity and highest transmission were found to occur at an annealing temperature of 350 degrees C. X-ray diffraction measurements revealed that the as deposited film had a strongly (222) oriented cubic structure. Annealing relieved the as deposited tensile strain and increased crystal perfection.