Highly conducting and transparent indium tin oxide (ITO) thin films were prepared on SiO2 glass and silicon substrates by pulsed laser ablation (PLA) from a 90 wt.% In2O3-10 wt.% SnO2 sintered ceramic target. The growths of ITO films under different oxygen pressures (Po-2) ranging from 1 x 10(-4)-5 x 10(-2) Torr at low substrate temperatures (T-s) between room temperature (RT) and 200 degrees C were investigated. The opto-electrical properties of the films were found to be strongly dependent on the Po-2 during the film deposition. Under a Po-2 of 1 x 10(-2) Torr, ITO films with low resistivity of 5.35 x 10(-4) and 1.75 x 10(-4) ht cm were obtained at RT(25 degrees C) and 200 degrees C, respectively. The films exhibited high carrier density and reasonably high Hall mobility at the optimal Po-2 region of 1 x 10(-2) to 1.5 x 10(-2) Torr. Optical transmittance in excess of 87% in the visible region of the solar spectrum was displayed by the films deposited at Po-2 greater than or equal to 1 X 10(-2) Torr and it was significantly reduced as the Po-2 decreases.