Enthalpies of vaporization of a large set of ionic liquids were predicted using the COSMO-RS ion-pair approach, at T= 298.15 K. Comparison with currently available experimental data of different methodological origin suggests +/- 10 ki mol(-1) as a preliminary realistic expectation range for the accuracy of COSMO-RS results. The obtained results were further used to derive the Hildebrand solubility parameters of the studied ionic liquids. While energetic subtleties due to different interaction modes in given ionic combinations are reflected in the respective enthalpies of vaporizations and are described by COSMO-RS, the presented COSMO-RS results additionally support a phenomenological data differentiation on a descriptive molecular level. (C) 2014 Elsevier B.V. All rights reserved.