The oxidation of the basal plane of zinc has been observed to have several distinct stages in a study using Auger electron spectroscopy and low-energy electron diffraction. For oxygen pressures between 10 −8 and 10 −6 Torr and substrate temperatures between liquid N 2 temperature and 425°K, the first stage of the oxide growth is described by a substrate temperature independent, linear rate law: dx dt = k 0P , where x is the film thickness, P is the oxygen pressure and k 0 is a constant with a magnitude of about 10 −3 cm/Torr·sec. The first stage of growth stops after an exposure of about 8×10 −5 Torr·sec after an oxide film several monolayers thick has formed. For T 300°K, the oxide film is an epitaxial single crystal with lattice constant parallel to the Zn substrate and equal to that of bulk zinc oxide. For T 250°K, no long range order was observed. Mechanisms which are consistent with the observed growth kinetics are discussed.