This paper presents an experimental study on various thermophysical properties of a new fluoroalkane, 1,1,1,3,3-pentafluorobutane (R365mfc). The thermal conductivity of R365mfc was measured in the liquid phase near saturation conditions at temperatures between 263 and 333 K using a parallel plate instrument with an uncertainty of less than ±5%. For the measurement of the saturated liquid density between 273 and 353 K, a vibrating tube instrument was used. The uncertainty of the density measurements is less than ±0.1%. In addition, experimental data have been obtained for R365mfc under saturation conditions over a wide temperature range from about 253 to 460 K using light scattering techniques. Light scattering from the bulk fluid has been applied for measuring both the thermal diffusivity and the sound speed in the liquid and vapor phases. Light scattering by surface waves on a horizontal liquid–vapor interface has been used for the simultaneous determination of the surface tension and kinematic viscosity of the liquid phase. With the light scattering techniques, uncertainties of less than ±1.0, ±0.5, ±1.0, and ±1.2% have been achieved for the thermal diffusivity, the sound speed, the kinematic viscosity, and the surface tension, respectively.