Properties like density and viscosity at (303.15, 313.15, and 323.15) K and refractive index at 303.15 K have been measured for binary mixtures of water + tetrahydrofuran and water + 1,4-dioxane. The excess molar volume (V-E) has been calculated from the density results. Viscosity and refractive index data have been used to compute respectively deviations in viscosity (Deltaeta) and molar refraction (DeltaR) of the mixtures. Excess molar volume and deviations in viscosity and molar refraction data have been fitted to the Redlich-Kister equation to calculate binary coefficients and standard deviations. Furthermore, literature published vapor-liquid equilibrium data of the mixtures have been used to construct x-y composition curves and compared with the pervaporation curves. Results of this study indicate the importance of the pervaporation technique for the separation of mixtures over that of simple distillation at the azeotropic composition. Permeate samples were analyzed by refractive index as well as gas chromatography measurements to get the exact content of water.