The relative permittivities (epsilon(r)) of dimethyl ether (DME) + carbon dioxide (CO2) mixtures [(0.25, 0.48, and 0.75) mass fraction of DME] were measured at (313 and 333) K in the pressure range (3.9 to 32.5) MPa. The Peng-Robinson equation of state was used to calculate the mixture compressed liquid densities (rho(calcd)), and the relative permittivity was fitted to rho(calcd), the temperature (T), and the mass fraction of DME (phi(1)) using a simple empirical equation.