Liquid-liquid equilibrium (LLE) data for the ternary system water + cyclohexane + acetic acid have been measured at (303.2 to 333.2) K under atmospheric pressure. The Othmer-Tobias and Bachman equations were used to check the reliability of the obtained tie-line data. The experimental data were correlated by NRTL (nonrandom two-liquid) activity coefficient model, and the relevant interaction parameters were regressed with the experimental data. The predicted values by NRTL method show good consistency with the measured data. The obtained interaction parameters can be used in the calculation of LLE for the ternary system water + cyclohexane + acetic acid as well as for the design and optimization of the related separation process.