In its first applications to ionic liquids the COSMO-RS method has shown to yield good qualitative and satisfying quantitative predictions for the activity coefficients of neutral compounds in ionic liquids and for binary mixtures of ionic liquids and neutral solvents. Since this success was achieved predictively, i.e. without any special parameterization, COSMO-RS since then has become a widely used and efficient tool for the prediction and screening of ionic liquid properties. In this article we give an overview of the various approaches and methodological differences used in this context by different groups. (C) 2010 Elsevier B.V. All rights reserved.