The vapour pressures of liquid (3,5; 2,6)-dimethylpyridine + n-hexane; + n-heptane and + n-octane mixtures were measured by a statistic method, respectively, between 263.15-353.15 K at 10 K intervals. The pure component vapour pressures data and those of mixtures were correlated with the Antoine equation. The excess enthalpies, at 303.15 K for those mixtures were measured by an isothermal calorimeter model C80 SETARAM. The molar excess Gibbs energies, calculated from the vapour liquid equilibrium data and the molar excess enthalpies compared satisfactorily with group contribution method (DISQUAC). (c) 2005 Elsevier B.V. All rights reserved.