Thin films of Nb doped SrTiOx (Nb-STO) have been fabricated on SrTiO3 (100) substrates by a pulsed laser deposition (PLD) technique and characterized by XRD, AFM, XPS and electrical resistivity. It was found that the preferred orientation of the deposited Nb-STO films was a-axis at a substrate temperature of 650 degrees C and oxygen pressures lower than 3 X 10(-1) Torr. The effect of the oxygen pressure on film properties such as surface roughness, lattice constants and chemical composition have been investigated. As the oxygen pressure was decreased, the film surface morphology improved. Furthermore, the lattice constant of the a-axis increased with decreasing oxygen pressure, in spite of there being no change in the Nb content detected in Nb-STO films.