The present study defines liquid-liquid equilibrium (LLE) data of (water-butyric acid-1-hexyl-3-methylimidazolium hexafluorophosphate [hmim][PF6]) ternary mixtures at T=298.2, 308.2 and 318.2 K and p =101.3 kPa. The results were then correlated with UNIQUAC and NRTL models. The experimentally obtained tie-line data quality was determined by the Othmer-Tobias and Hand correlations. Distribution coefficients and separation factors were calculated from the experimental data. It was observed that the temperature change has a limited effect on the equilibrium data in the studied temperature range.