A group contribution method developed by Valderrama and Robles in 2007 is updated and extended to calculate the critical properties, the normal boiling temperature, and the acentric factor of metal-containing ionic liquids (MILs). The proposed extension is valid for all types of ionic liquid, including MILs, for which the values of the contributions are reported in this paper. Values of 29 new metal groups are determined, and the estimated properties of 2574 new ionic liquids are tested for consistency using two independent tests, one for density and another for vapor pressure, as previously proposed by the authors. A spreadsheet for calculating the critical properties and performing the tests is provided as Supporting Information. The spreadsheet file includes at present the properties for 4156 ionic liquids of molar mass going from 77 to 1730, including MILs.