Isobaric vapor-liquid-liquid equilibrium (VLLE) data for the ternary system cyclohexane + water + acetic acid were measured at 101.3 kPa. A modified dynamic recirculating still equipped with a mixing section was used to determine the VLLE. The experimental data indicate that a binary heterogeneous azeotrope is present at 342.16K with a composition of 0.3 and 0.7 mole fractions of water and cyclohexane, respectively. The VLLE data have been used to test the reliability of the UNIQUAC and NRTL models in the prediction of VLLE. The two model parameters were obtained using VLE and LLE data correlation, respectively. The results indicate that the NRTL model has an acceptable prediction of the VLLE data, and the UNIQUAC model has a prediction of the heterogeneous region. (C) 2013 Elsevier B.V. All rights reserved.