This paper reports experimental densities and surface tensions of the ternary system propyl propanoate + hexane + p-xylene at a temperature of 298.15 K and atmospheric pressure, over the whole composition range. We present here the experimental densities and surface tensions of the binary system hexane + p-xylene and the tertiary system propyl propanoate + hexane + p-xylene. The excess molar volumes and the surface tension deviations of these mixtures have been calculated. Finally, we will compare the experimental data of the surface tension deviations with different theoretical and empirical approximations.