Liquid-liquid equilibrium (LLE) data have been measured for the ternary system 4-methyl-2 pentanone + 2-butanol + water at (283.15 and 333.15) K. Experimental results show a low influence of temperature on immiscibility zone size and shape. The NRTL and UNIQUAC models were applied to correlate the ternary system at (283.15 and 333.15) K, and the interaction parameters obtained from both models successfully correlated the equilibrium compositions. Moreover, isobaric vapor liquid liquid equilibrium (VLLE) is measured for this ternary mixture at 101.3 kPa. The experimental data were compared with the estimation from LLE binary interaction parameters using NRTL and UNIQUAC models, as well as the correlation obtained with these models. The prediction of the UNIFAC LL model has been obtained and compared with the previous results, to confirm the necessity to obtain experimental data in this type of system.