Isobaric vapor-liquid equilibrium (VLE) data were determined at 20 kPa for the three binary mixtures composed of octane + p, o, m-xylene by using a recirculation type still. All the data passed the thermodynamics test and no azeotropic behavior was observed. The experimental results were used as a basis to check the validity of two predictive models, the UNIFAC (DORTMUND) and COSMO-RS. These new VLE data were also correlated with the Wilson, NRTL, and UNIQUAC activity coefficient models. (C) 2013 Elsevier B.V. All rights reserved.