This paper describes the preparation of organic-inorganic (0-1) UV-cured hybrid systems as effective coatings for different substrates. Starting from methacrylic-siloxane monomers, two hybrid systems were produced, through hydrolysis and condensation reactions, and analyzed as a function of their composition. For comparison purposes, two control formulations, i.e. possessing the same organic composition of each hybrid, were also produced. In all the systems, the cross-linking reactions of the acrylic groups in the oligomer took place via free radical photo-polymerization reactions, controlled by a suitable photoinitiator. The first part of the work was devoted to the analysis of the dimension and the nature of the silica nanodomains, well dispersed within the cross-linked organic phase. To this aim, DLS and XRD analyses were firstly performed at different times from the preparation of the O-I systems. Both hybrids were subsequently applied on a glass substrate and photopolymerized by UV lamp. Several properties (glass transition temperature, transparency, scratch and surface hardness and contact angle) were, then, measured on applied hybrid coatings and compared to those found for the corresponding control organic formulations. A substantial improvement of all the properties measured was found, especially in the case of the hybrid possessing the highest amount of nanosilica. This latter was, therefore, identified as suitable as protective coating for different substrates.