The azeotropic temperatures and compositions for benzene + 2-methyl-2-propanol and cyclohexane + 2-methyl-2-propanol binary systems and benzene + cyclohexane + 2-propanol and benzene + cyclohexane + 2-methyl-2-propanol ternary systems are determined at seven pressures from 13.5 to 101.5 kPa by an azeotropy apparatus using the rectification method. The ternary azeotropic temperatures and compositions are predicted by the Wilson activity coefficient model with the energy parameters estimated from the azeotropic temperatures and compositions for the corresponding binary systems. The predictions compare satisfactorily with the experimental results and indicate that the Wilson equation can be used for predicting ternary azeotropic points.