Gold thin films were deposited by pulsed laser deposition in presence of an O-2 atmosphere. The background gas pressure varied from 6.7 to 119.7 Pa and the target-to-substrate distance was kept constant at 30 mm. Structural analysis of the deposited films was conducted by means of X-ray diffraction and X-ray photoelectron spectroscopy. Both X-ray diffraction and X-ray photoelectron spectroscopy analysis show that gold oxide is formed during reactive pulsed laser deposition of gold. The gold oxide content of the film increases up to about 85% as the O-2 pressure reaches 53.2 Pa and remains constant for higher pressure. The stoichiometry of the gold oxide phase [O]/[Au] is 1.25, close to that expected for AU(2)O(3), and does not vary with the O-2 pressure. Gold oxide decomposes slowly with time upon exposure to the ambient atmosphere. (C) 2004 Elsevier B.V. All rights reserved.