Gaseous PVT property measurements for difluoromethane (HFC-32) + pentafluoroethane (HFC-125) mixtures at 0.8191 (66.25 mass %), 0.5794 (37.38 mass %), and 0.4320 (24.79 mass %) mole fractions of HFC-32 are presented. Two hundred PVTx data points of this binary system were measured using Burnett isochoric methods in the range of temperature from (303.15 to 373.15) K, for pressures up to 3.246 MPa, and for densities up to 121 kg(.)m(-3). The experimental uncertainties are estimated to be within +/-10 mK for temperature, +/-0.3 kPa for pressure, 10.10% for density, and 0.1 mol % for composition. The temperature dependence of the second and third virial coefficients, along with the cross second and third virial coefficients, was also determined.