Isobaric vapour-liquid equilibrium data have been measured for allyl alcohol and trichlorethylene at 200, 500 and 705 Torr for ten compositions spread evenly over the entire liquid mole fraction range, employing a Swietoslawski-type ebulliometer. The mole fraction composition vs. boiling point data are well represented by the Wilson model. The optimum Wilson parameters are used to calculate the vapour compositions, activity coefficients and the excess Gibbs free energy.