Diesel fuel composition suitable for use in an internal combustion engine comprising: (a) 2 mass % to 30 mass % of kerosene having a kinematic viscosity at 40° C. of 1.5 mm2/s or less and a density of 810 kg/m3 or less; (b) 2 mass % to 20 mass % of Fischer-Tropsch derived base oil having a kinematic viscosity at 40° C. of 7.5 mm2/s or greater and a density of 790 kg/m3 or greater; and (c) diesel base fuel. The diesel fuel composition of the present invention provides improved cold flow properties while simultaneously maintaining other properties such as viscosity and density within diesel fuel specification requirements.