Solubilities between 323.15 and 413.15 K and equilibrium data between 323.15 and 373.15 K for the water + 4-hydroxy-4-methyl-2-pentanone + benzyl alcohol ternary system are reported in order to obtain the extractive properties of benzyl alcohol for separating 4-hydroxy-4-methyl-2-pentanone from aqueous solutions, and the influence of temperature. Solubility data of the binary system water + benzyl alcohol are also reported. The effect of temperature on liquid-liquid phase equilibrium was determined, and its consequences are discussed. Tie-line data were satisfactorily correlated by the Othmer and Tobias method [Othmer, D.F, and Tobias, P.E., 1942. Tie line correlation. Ind. Eng. Chem., 34 : 693-696]. The experimental data were compared with values calculated by the NRTL and UNIQUAC equations for the ternary mixture, and the predictions obtained by the UNIFAC method are also included. While the water + benzyl alcohol system has a binary upper critical solution temperature at 421.65 K, no ternary one was observed. It is concluded that benzyl alcohol is appropriate for the extraction process when the mass fraction of the consolute component in the extract phase is less than 0.22, not as suitable when this concentration is greater. The small difference in the extractive properties between 348.15 K and room temperature shows that it is unnecessary to carry out the extraction at a higher temperature.