Liquid-liquid equilibrium (LLE) data for the ternary system of water + benzaldehyde + toluene have been determined at (303.2-343.2) K under atmospheric pressure. The Othmer-Tobias and the Hand correlations were used to check the reliability of the experimental data. The obtained LLE data were correlated by both the NRTL and UNIQUAC activity coefficient models. The relevant interaction parameters were extracted by the regression of the experimental data. The calculated values by these two models show good consistency with the measured data. The relative-mean-standard deviations obtained is 0.82% by the NRTL model and 0.12% by the UNIQUAC model. The obtained interaction parameters might be used in the calculation of LLE for the ternary system water + benzaldehyde + toluene as well as for the design and optimization of the related separation process. (C) 2014 Elsevier B.V. All rights reserved.