The thermodynamic properties of potassium chloride aqueous solutions are correlated using a Pitzer model. The modeling approach used in this study is similar to that applied by Archer [10] for NaCl aqueous solutions that is currently considered to be the most accurate correlation of properties of electrolytes in a wide range of temperatures, pressures and compositions. Model parameters were fitted to 145 experimental data sets on various thermodynamic properties, of the KCl-H2O system published to date. The proposed model is capable reproducing the measured data to high accuracy at temperatures ranging from freezing point of a solution to 600 K, pressures from saturated vapor to 150 MPa, and concentrations up to the solubility limit. (C) 2017 Elsevier B.V. All rights reserved.