Densities, viscosities, and surface tension have been measured as a function of composition for the binary liquid mixture of diethylene glycol diethyl ether + water at 293.15 K under atmospheric pressure. Densities were determined using a capillary pycnometer. Viscosities were measured with a Ubbelohde capillary viscometer. Surface tension was measured by means of the drop-volume technique. The estimated uncertainties of the measurements were +/-0.1% for density, +/-0.3% for viscosity, and +/-0.04 mN(.)m(-1) for surface tension. Liquid-liquid equilibrium data were also measured for the binary mixture in the 14 temperature range from 301.15 K to 363.15 K. The compositions of both the top and bottom phases were analyzed by gas chromatography.