Abstract: A process for the production of a synthetic low sulphur diesel fuel and a low soot emission aviation fuel is disclosed. The process includes fractionation of a Low Temperature Fischer-Tropsch feedstock into a light kerosene fraction and a heaver diesel fraction in a volumetric ratio of at least 1:2 to form the light kerosene fraction having a smoke point greater than 50 mm, a freezing point of below ?47° C., a BOCLE lubricity wear scar less than 0.85 mm, and an anti-oxidant additiveless thermal stability tube deposit rating at 260° C. of less than 1 useable as a low soot emission aviation fuel and/or an aviation fuel blend stock, and the heavier diesel fraction having CFPP according to IP309 of below ?5° C., a density@20° C. of at least 0.78 kg/l, and a viscosity@40° C. of above 2 cSt useable as a synthetic low sulphur diesel fuel and/or a diesel fuel blend stock.