Indentations using a Berkovich indenter were performed in order to analyze the mechanical properties of a SiO2-filled methyltrimethoxysilane (MTMS) coating. The coatings were deposited using a spin-coating technique. The elastic modulus and the hardness were determined on the basis of the load-displacement curve. The effects of coating thickness, composition and substrate material were investigated. Cracks, delamination and chipping were observed and used to assess the fracture toughness of the coating and the interface.