Pressure and temperature data were experimentally measured for binary supercritical mixtures of carbon dioxide and 1,1-difluoroethene. The temperature range for the experiments was from 310 K to 370 K. The pressure range was from 7.0 MPa to 31.0 MPa. It was determined that the Peng-Robinson equation of state can predict fluid behavior of supercritical carbon dioxide and 1,1-difluoroethene with a deviation of 2.5% ± 0.1%. A binary interaction parameter was obtained from a regression analysis over the temperature range of interest.