The group contribution method proposed by Valderrama and Robles in 2007 and extended by Valderrama et al. in 2008 to estimate the critical properties of ionic liquids is revised and new groups have been included. The method originally proposed has been used by several authors in applications Such as high pressure phase equilibrium, density correlations, heat capacity estimations, and consistency tests for mixture data. Therefore, it is important to have a consistent and reliable method so all applications consider the same assumptions and values for the critical properties. The values previously reported by the authors are recalculated, unifying criteria for the names of the ionic liquids, for the assignment of the groups forming the molecules, and for the equivalence of groups. Also, a spreadsheet file that allows,my reader to calculate the critical properties of any ionic liquid containing the 44 groups defined by the method is provided as Supporting Information.