Sol-gel methods have been recognized as interesting procedures to prepare catalysts. The versatility of the sol-gel techniques allows control of the texture, composition, homogeneity and structural properties of solids, and makes possible production of tailored materials such as dispersed metals, oxidic catalysts and chemically modified supports. In this work, different approaches, described in the literature, to prepare catalysts by the sol-gel methods, including both aerogel and xerogel active solids, are reviewed. In parallel, some of the most relevant catalytic reactions carried out with sol-gel catalysts are evaluated.