The (vapour + liquid) equilibria (VLE) data for the binary system of glycidyl butyrate (1) and epichlorohydrin (2) was studied at (100, 88.66, and 56) kPa. Azeotropic behaviour has not been found in this work. The activity coefficients were obtained by the non-linear least squares method based on minimization from the equilibrium data. Average relative deviations between calculated values and the experimental data of temperature are all lower than 0.99% for the three models at the three different pressures investigated. The root mean square deviations (RMSD) of gas phase compositions y(1) and temperatures are all lower than 0.0099 and 1.1 K for 100 kPa, 0.0094 and 4.5 K for 88.66 kPa and 0.0095 and 3.7 K for 56 kPa. The thermodynamic consistency of the calculated data is checked by the Herrington method. The experimental VLE data are compared with the correlated values obtained by means of the NRTL, UNIQUAC, and Wilson models. (c) 2012 Elsevier Ltd. All rights reserved.