Epoxy coatings containing sepiolite as inorganic reinforcement was obtained by UV-induced polymerization. An increase in epoxy group conversion was achieved in the presence of the inorganic filler; this was due to the strong interactions between the high density of silanol groups present on the sepiolite surface and the carbocationic growing chain. Improved properties of the cured coatings were achieved such as higher T (g), higher modulus, higher surface hardness. Interface-dominated materials are obtained since the high interfacial area plays a major role in the final composite properties.