A series of polysiloxanes appended with eugenol functionalities has been synthesized through Pt-catalyzed hydrosilylation reactions. These eugenol-modified polysiloxanes were blended with commercial epoxy resins as anticorrosion additives at a low loading percent (2.5 wt%), and the properties of the resulting coatings were investigated by chemical, electrochemical and microscopic characterizations. It was found that the eugenol-modified polysiloxane additives can significantly increase the performance of epoxy resin coatings in terms of thermal stability, hydrophobicity and resistance to water penetration. Our studies demonstrate that eugenol-modified polysiloxanes are a new class of anticorrosion material with potential applications in marine corrosion control and protection.