We present new vapour pressures and the (p, rho(n), T) surface of CF3CHF2 (pentafluoroethane, designated R125 by the refrigeration industry) in the temperature range T = 273 K to 363 K. The (p, rho(n), T) measurements are for the gas phase at densities up to approximately the critical density. The static vapour pressures reported here have been combined with previous ebulliometric measurements made in this laboratory at lower temperatures. Correlating equations are given for the vapour pressures from T = 220 K to the critical temperature : T-c = 339.30 K. A virial equation has been used to correlate the (p, rho(n), T) surface at amount-of-substance densities up to 1600 mol.m(-3). Second and third virial coefficients have been derived from the (p, rho(n), T) measurements.