Two and three phase equilibrium data obtained from the ternary system water/2-butyloxyethanol/n-decane at 25, 30 and 35 degrees C are presented in this paper together with the points of the binodal curves. The experimental tie-lines are correlated with the NRTL and UNIQUAC models using a computational algorithm developed by Brandani to obtain the model parameters and to perform phase equilibria calculations.