Liquid-liquid equilibria (LLE) data for the ternary system of n-butyl acetate + pyrocatechol + water were measured at 101.3 kPa over the temperature range of 298.15-318.15 K. Phase diagrams were obtained by determining the tie-line data. The LLE experimental data for the system were correlated-with the nonrandom two-liquid (NRTL) and universal quasichemical (UNIQUAC) models. The average, root-mean-square deviations (RMSD) of the NRTL and UNIQUAC models were 0:0114 and 0.0200. Both models correlated the experimental tie-line data successfully, while the correlation of the UNIQUAC model was inferior to that of the NRTL model.