Liquid-liquid equilibria for the ternary system water + acetic acid + 1-pentanol were measured over a temperature range of (288 to 323) K. The results were used to estimate the interaction parameters between each of the three compounds for the NRTL and UNIQUAC models and between each of the main groups of H2O, CH2 (paraffinic CH2), OH, and COOH for the UNIFAC model as a function of temperature. The estimated interaction parameters were successfully used to predict the equilibrium compositions by the three models. The NRTL and UNIQUAC models were almost equally good in predicting the overall equilibrium compositions of the studied system. The UNIFAC model satisfactorily predicted the equilibrium compositions. On the basis of this work, the distribution coefficients were also calculated and compared with the experimental values.