The aim of this work was to study the effect of the incorporation of cerium nitrate in a silica-methacrylate sol–gel hybrid matrix reinforced with silica nanoparticles. Sols, coatings and powders have been studied, focusing specially in the determination of the redox ratio Ce3+/Ce4+ and films structure. Sols have been characterised using viscosity measurements and FT-IR spectroscopy, and powders and coatings obtained with different Ce contents through UV–Vis and FT-IR spectroscopy, TGA, TEM, AFM and FE-SEM. The goal was to reach the best compromise between maximum cerium concentration and coating stability to better understand the mechanisms acting in active anti-corrosive processes.