In this paper, the deposition conditions and the characterization properties of the indium oxide (10) and indium tin oxide (ITO) thin films deposited by a reactive thermal deposition technique using the indium, indium-tin alloy sources are reported. The actively involved parameters during deposition have been identified for various substrate temperatures. The effect of oxygen partial pressure in evaporation has been identified. The indium-tin alloy source which was used in this work was prepared by hot zone diffusion technique. The structural, optical, and electrical properties have been characterized using optical microscope, x-ray diffractometer, ultraviolet spectrophotometer, and Hall effect measurement setup. The uniformity of the deposited films and the uniformity of the substrate surface effect on the deposited thin films were analyzed through sheet resistance measurements. The depositions were carried out on glass and quartz substrates. Good optical transmittance (99%) was achieved for 740 nm wavelength and above. The absorbance spectrum exhibit a value of 2% absorbance for IO/quartz structures. Large area (5.0 × 3.8 cm) film with unique optical properties is also reported here. © 1995 The Metallurgical of Society of AIME.