Vapour pressures of (cyclohexane + 1, 1,2,2-tetrachloroethane (TCANE)) or (cyclohexane + tetrachloroethene (TCENE)) Mixtures at nine temperatures between 283.15 and 323.15 K were measured by a static method. The reduction of the vapour pressures to obtain activity coefficients and excess molar Gibbs energies was carried out by fitting the vapour-pressure data to the Redlich-Kister polynomial according to Barker's method. A comparative analysis about the thermodynamic behaviour of both systems is performed, taking into account the resonance effect in tetrachloroethene. For 1,1,2,2-tetrachloroethane + cyclohexane mixtures, we have tested the DISQUAC model observing that reproduces satisfactorily the G(E) experimental values at all temperatures. (C) 2003 Elsevier B.V. All rights reserved.