Dynamic surface tension measurements of molten aluminium have been carried out under different monitored oxygen partial pressures in the temperature range 873–1323K with the aim of experimentally confirming the behaviour of molten metals in the presence of traces of oxygen as predicted by theoretical models [Ratto M, Ricci E, Arato E, Costa P. Metall Mater Trans B 1998;32B:903; Castello P, Ricci E, Passerone A, Costa P. J Mater Sci 1994;29:6104]. The procedures necessary to obtain experimental validation of the theoretical oxidation–deoxidation curve at high temperatures under both low total pressure and atmospheric pressure are presented.