In this work the isobaric vapor-liquid equilibrium (VLE) data for hexane + 1-decene and octane + 1-decene systems have been measured at 101.33 kPa. The results were correlated using the Margules, Van Laar, Wilson, and UNIQUAC equations for the liquid phase activity coefficients. The average deviations fall within the same range for all models and agree well with experimental VLE data obtained in this work. Also, the experimental results were compared with the predictions of the modified UNIFAC group contribution method, which suggests that UNIFAC works well for unbranched alkane + 1-alkene systems.