The structural and chemical properties of silica-alumina xerogels obtained using the sol-gel process were investigated. As methods of characterization, sorption of nitrogen, thermal analysis, and potentiometric titration were chosen. The results obtained showed a high contribution of micropores in the structure of the silica-alumina xerogels, which decreased with increasing content of aluminum. An investigation of the acidic-basic properties of the surfaces showed the presence of centers which have not been detected in commercial catalysts obtained in a more traditional way. These centers may be the result of synergy between our components and/or different coordinations between the cations.