Molar excess Gibbs free energy of mixing values for 1-propanol or 2-propanol + benzene, toluene, o- m- or p-xylene at 298.15 K have been calculated by the Barker method from vapour pressure data measured by a static method. The free energies of mixing for these binary systems are also predicted in terms of the Mecke-Kempter type of association model with a Flory contribution term using two interaction parameters. The predicted values agree reasonably well with the experimental values.