An experimental study was conducted to investigate the effects of four different additives on pour point and cloud point temperatures of a diesel fuel. Sample mixtures were prepared in different volumetric percentages of four different additives (Ethanol, Toluene, n-Heptane and Xylene) and diesel fuel mixture. Pour point and cloud point temperatures of the blends were measured using standard ASTM D2500 and ASTM D97-96a methods, respectively. Introducing the additives to the diesel fuel did not lead to a significant reduction in cloud point temperature of the fuel. In fact, the greatest obtained reduction in cloud point temperature was achieved using 20 vol% or more of Toluene-diesel fuel mixtures. Although cloud points did not change significantly, even the slightest amounts of additives caused a high reduction in the pour point temperature of the fuel. Ethanol was the most effective additive in lowering the pour point temperature of the fuel. A 20% ethanol-fuel mixture caused nearly a 30° reduction in the fuel pour point temperature. Therefore, knowing that none of the additives has a significant effect on cloud point temperature, while the greatest reduction in pour point temperature is achieved using ethanol even in low Vol%s, it can be concluded that the most efficient additive among these four additives to alter cold flow properties of a certain diesel fuel is Ethanol. © 2018 Southwest Petroleum University