Isobaric vapor-liquid equilibrium data for the ternary system 2- methyl-1-butanol (1) + 3- methyl-1-butanol (2) + ethylene glycol (3) were measured in a modified Rose recirculation still at 101.3 kPa. The experimental data were satisfactorily correlated with the Wilson equation. They were also compared with the predictions by Weidlich's modified UNIFAC group contribution method, and the deviations were also small. The both models are satisfied with the accuracy demanded of process development, design, and simulation.