Vegetable oils are excellent renewable raw materials for thermosetting polymers. By the direct polymerization of triglyceride C=C, we obtained organic-inorganic hybrid materials with promising properties for optical applications by the hydrosilylation of alkenyl-terminated fatty acid derivatives. The presence of double bonds in triglycerides makes it possible to attach some functional groups through chemical modification, and we describe various chemical pathways for functionalizing triglycerides and fatty acids. Epoxidation is one of the most interesting chemical modifications that leads to epoxidized vegetable oils. We report the preparation of biobased polyhedral oligomeric silsesquioxanes-nanocomposites from epoxidized linseed oil. Moreover, we describe the preparation of a new family of epoxidized methyl oleate-based polyether polyols, which were used in the synthesis of polyurethanes with specific applications: silicon-containing polyurethanes with enhanced flame-retardant properties and polyurethane networks with potential applications in biomedicine. An enone-containing triglyceride derivative was obtained, by an environmentally friendly chemical procedure from high oleic sunflower oil that could be cross-linked with diamines. In a similar way, triglycerides containing secondary allylic alcohols can be obtained that can be further functionalized with acrylate or phosphorus-containing derivatives to obtain flame-retardant thermosets.