Experimental liquid-liquid equilibria data of dilute hydroquinone concentration were determined for the ternary system methyl isobutyl ketone + water + hydroquinone at (25, 40, and 50) degrees C under atmospheric pressure. The experimental data were satisfactorily correlated with the UNIQUAC equation and the NRTL equation. The relative root-mean-square deviations and absolute mean deviations between the calculated and the experimental value are less than 1.2%.