In recent years, environmental considerations, the potential for supply disruptions, and rising fuel prices have led to the development of alternative diesel fuels produced from nonpetroleum feedstocks. It is important to characterize the properties of these fuels in order to assess the degree of departure of the alternative fuels from the petroleum-derived fuels. One of the most important properties to use for this purpose is the volatility, as expressed by the distillation curve. In this paper, we present advanced distillation curve measurements of three prototype alternative diesel fuels and compare the distillation curve, composition, and combustion enthalpy to those of petroleum-derived diesel fuel. We studied two FischerTropsch diesel fuels, one synthesized from coal-derived gas and one produced from natural gas, and one renewable diesel fuel composed of hydrotreated animal and vegetable fats. We found that the distillation curves of the three alternative diesel fuels are similar to those of those of petroleum-derived diesel fuel; deviating at most by 30 degrees C from the distillation curve of petroleum-derived diesel fuel. In general, the most significant, deviations from petroleum-derived diesel fuel are found in the light'. region (10-30% distillate volume fraction) and the "heavy" region (70-90% distillate volume fraction) of the distillation curve. The diesel fuel made from natural gas was most Similar to petroleum-derived diesel in its volatility and combustion enthalpy.