Successful practical application of ionic liquid (IL) membranes requires good understanding of their basic transport properties and the role of the IL itself and its polymeric support. Within this work, two approaches to the calculation of mass transfer coefficients of gases in supported ionic liquid membranes were applied. The first one applies the models and data reported on diffusivity and solubility of gases in pure ionic liquids in the literature, in combination with porosity and tortuosity of the support. The second one is based on fitting of experimental data obtained from two ionic liquid membranes. The results of both approaches were compared and used to predict the properties of ionic liquid membranes. It was found that the model based on data of pure liquids overestimated the mass transfer coefficient significantly. (C) 2013 Elsevier B.V. All rights reserved.