The viscosities of dimethyl ether in the temperature range of (243 to 373) K from saturated pressure up to 30 MPa are reported. These new experimental data were measured with a vibrating-wire viscometer. The combined expanded uncertainty of the results with a level of confidence of 0.95 (k = 2) is about +/- 2.0 % over all ranges of temperature and pressure. The experimental data are used to develop correlations for the viscosity, including a saturated liquid equation and a multiparameter formulation covering liquid and vapor region. On the basis of the uncertainty of and comparisons with the experimental data, the estimated uncertainty of viscosity correlation is 2 % in the liquid phase and 3 % in the gas region.