The effect of crude oil properties on hydrodesulfurized diesel quality was studied in a hydrotreating fixed-bed pilot plant. Three HDT feeds were prepared by blending the straight-run middle distillates obtained by TBP fractionation of crude oils in the following volumetric ratios: 60% straight-run gas oil, 20% kerosene, and 20% jet fuel. Pilot plant experiments were conducted at constant reaction pressure (54 kg/cm(2)) and hydrogen-to-oil ratio (2000 ft(3)/bbl). The effect of reaction temperature and liquid hourly space velocity were studied in the range of 340-360 degreesC and 1.5-2.0 h(-1), respectively, over two commercial catalysts (NiMo and CoMo). The effect of crude oil properties on product quality is analyzed in terms of hydrodesulfurization, hydrodenitrogenation, and aromatics removal.