The hydrodesulfurization and cracking activity of NiMo sulfided catalysts supported on Al-, Ti-, and Zr-modified SBA-15 was measured using the HDS of thiophene and cracking of cumene as model reactions. The results were used to analyze the effect of each heteroatom on the two reactions, and the existence of a relationship between HDS activity and the catalysts acid properties. The HDS activity of sulfided NiMo catalysts supported on Al-, Ti-, or Zr-modified SBA-15 depends significantly on the nature of the heteroatom used to modify the SBA-15 support. The HDS activity trend displayed by the catalysts was NiMo/Al20-SBA-15 > NiMo/Ti20-SBA-15 > NiMo/Zr20-SBA-15. This trend was similar for the cumene cracking reaction. The results indicate that Bronsted acidity favors hydrodesulfutization.