The oxidation kinetics of iron, aluminium and titanium films have been studied in the temperature range 50-200 degrees C at a pressure of 0.7 Pa with a piezoelectric quartz microbalance. For titanium, additional measurements in the pressure range 7 x 10(-3)-70 Pa have been carried out. All three metals under investigation showed qualitatively common features in their oxidation behaviour : a very fast initial oxygen absorption step, completed in less than 1 min, followed by a slow, temperature-independent oxide growth with logarithmic time law at lower temperatures, and an enhancement of the oxidation rate at higher temperatures. The oxidation curves are compared with the results of model calculations based on the Cabrera-Mott theory.