The removal of sulfur and nitrogen compounds from oil derivatives is fundamental to fulfill the new environmental laws. Traditionally, this removal is carried out through hydrotreatment processes; however, regarding environmental and economic issues, the refining oil industry has been studying adsorption processes to reduce sulfur and nitrogen compound levels in diesel streams. The aim of this work was to study the influence of chemical composition and acid–base properties of commercial alumina, silica, and silica–alumina samples on the removal of sulfur and nitrogen compounds from diesel streams. It was observed that acid and textural properties and surface composition influence the adsorptive capacity of the samples. The results indicated that the adsorbents tested were more efficient for the removal of nitrogen compounds. Kinetic and adsorption experiments using model fuel containing sulfur and nitrogen compounds were also carried out. Freundlich and Sips models described the adsorption of 4,6-dimethyldibenzothiophene and quinoline on silica–alumina, respectively.