Measurements of the density and viscosity of diethyl ether (DEE) are reported over the temperature range from 243 to 373 K and at pressures up to 20 MPa. The measurements were performed simultaneously using a vibrating-wire instrument operated in the forced mode of oscillation. The overall uncertainties of these results are +/- 2.0% in viscosity and +/- 0.2% in density. Correlations for both density and viscosity are presented, and comparisons are made with various sets of results from the literature. The maximum absolute deviation and the average absolute deviation of the measurement data from the correlation for viscosity are 1.17% and 0.29%, respectively, and for the density are 0.12% and 0.03%. (C) 2008 Elsevier B.V. All rights reserved.