Indium tin oxide thin films (thickness similar to 300 nm) have been deposited on glass at the substrate temperature of 65 degrees C by radio frequency magnetron sputtering with the power density of 1.25W cm(-2) under argon atmosphere and annealed subsequently in silicon oil at 200 degrees and 350 degrees C to investigate systematically the effects on their structural, optical and electrical properties. As-deposited thin films after annealing at 350 degrees C exhibit marked changes in the microstructure with emergence of crystallites (average size similar to 51 nm), high optical transmittance (similar to 86%) in the visible range, and electrical resistivity as low as 1.24 x 10(-3) Omega-cm with high figure of merit of 5.35 x 10(-3) Omega-1 square - indicating their suitability as transparent conducting anode for optoelectronic devices. Further, the above findings are compared with those observed in case of films annealed in vacuum (similar to 4 x 10(-4) Pa) at 350 degrees C. (C) 2014 Elsevier B.V. All rights reserved.