Diffusivity of oxygen in liquid bismuth was measured by potentiostatic method and is given by lg(D-o(Bi)/cm(2) . s(-1))(+/- 0.042) = -3.706 - 1377/(T K-1) (804 < T/K < 1090). Activity of oxygen in bismuth was determined by coulometric titrations and using the measured data standard free energy of dissolution of oxygen in liquid bismuth was derived for the reaction: 1/2O(2) (g) = [O](Bi) (at.%) and is given by Delta G(O(Bi))(o)/(J . g-atom O-1)(+/- 720) = -108784 + 20.356T K-1 (753 < T/K < 1020). Using the above data and Gibbs free energy of formation of Bi2O3 (s), solubility of oxygen in liquid bismuth was derived as a function of temperature and is given by the following expressions: lg(S/at%O)(+/- 0.05) = -4476/T K-1 +4.05 (753 < T/K < 988); lg(S/at.%O)(+/-0.04) -3786/T K-1 + 3.36 (988 < T/K < 1020). The present data on solubility of oxygen in liquid bismuth is compared with the literature data. (C) 2005 Elsevier Ltd. All rights reserved.