The density and surface tension values are presented that represent the best current knowledge of these properties for members of the homologous series of 1-C-n-3-methylimidazolium chlorides. To identify these values, a method was used based on the consistency requirement between selected background experimental data and group contribution models of known best achievable accuracy. The models have been developed using our own and other authors' data. For this purpose 64 and 119 new experimental data on the density and surface tension, respectively, have been measured for [C1IM][Cl] and [CnMIM][Cl] with n = 2, 3, 4, 6, and 10 at temperatures from (263 to 365) K and at the pressure of 0.1 MPa. The density was measured using the buoyancy method while the surface tension was measured by the Wilhelmy plate and du Nouy ring method in parallel. The respective expanded combined uncertainties at the 0.95 confidence level of the resultant means of sets of individual measurements performed at a given temperature do not exceed 1 kg.m(-3), 0.07 mN.m(-1) and 1 mN.m(-1). The estimated maximum deviations of the obtained recommended values from the true density and surface tension values are 0.1 kg.m(-3) and 0.15 mN.m(-1), respectively. (C) 2017 Elsevier B.V. All rights reserved.