Isobaric (vapour + liquid) equilibrium (VLE) data for {2-propanol (1) + water (2) + ammonium thiocyanate (3)} were obtained at 101.3 kPa experimentally. An all-glass Fischer-Labodest type still capable of handling pressures from (0.25 to 400) kPa and temperatures up to 523.15 K was used. (Vapour + liquid) equilibrium data of (2-propanol + water) were also obtained at 101.3 kPa experimentally. An equation is proposed to fit the data of salt-containing systems using dimensionless groups called relative ratio. The proposed model was also tested for the salt-containing systems given from the literature. (c) 2006 Elsevier Ltd. All rights reserved.