This paper reports the ternary liquid-liquid equilibrium (LLE) data for water-propionic acid-ethylbenzene at T = (308.2 and 318.2) K and water-propionic acid-benzyl benzoate systems at T = (298.2, 308.2, and 318.2) K and p = 0.1 MPa for the first time. Solubility data and mutual solubilities between ethylbenzene or benzyl benzoate and water were measured using the traditional cloud point method. Tie lines were experimentally obtained using acidimetric titration, the Karl Fisher titration and the refractive index measurements on the both aqueous and organic phases. The ternary systems exhibit type-1 phase behavior. The reliability of the tie-line data exhibited linear behavior in the Hand and Othmer-Tobias correlation plots. The experimental tie line data were correlated using the nonrandom two-liquid and universal quasichemical thermodynamic models, and the corresponding binary interaction parameters were determined. The results demonstrate the capability of the two models in correlation and description of the phase behavior of the related ternary systems with acceptable average root-mean-square deviation (rmsd) values. As a result, temperature has only a minor effect on the LLE behavior of the system containing benzyl benzoate.