The solubility and partition coefficient of p-toluic acid in p-xylene and water at ambient pressure were measured over the temperature range of 303.2-353.2 K. The measured solubility data and partition coefficient data were well correlated by the NRTL equation. The well-documented p-toluic acid-water system was used to validate the reliability of the sampling and analytical techniques employed. The results showed that the solubility of p-toluic acid in p-xylene and water increases with the temperature increase. The partition coefficient of p-toluic acid between p-xylene and water increases with the increasing initial mass of p-toluic acid, but decreases with the rising temperature. The equilibrium data of the ternary system are essential for the extraction process design and scale-up in the PTA wastewater recovery and treatment. (C) 2012 Elsevier B.V. All rights reserved.