Isobaric vapor-liquid equilibria are measured for 1-hexene + o-xylene, + m-xylene, + p-xylene, + toluene, and + ethylbenzene at 101.3 kPa, using a dynamic still with circulation in both of the phases. The experimental data are tested for thermodynamic consistency and could be represented well by the Wilson and UNIQUAC equations, with the latter being far better. A comparative analysis of the application of the group contribution methods ASOG, original UNIFAC, modified UNIFAC-Dortmund, and modified UNIFAC-Lyngby to the mixtures of this study showed that UNIFAC-Lyngby gives better results.