In this study, we used both silk fibroin nanofibers (nSFs) and rice husk silica nanoparticles as epoxy (EP) resin reinforcement materials to improve the modes I and II interlaminar fracture toughness of EP-filled carbon fiber-based (CF/EP) composites. The nSFs were obtained by electrospinning, while the rice husk silica nanoparticles were obtained via acidic and thermal treatments. The results showed that the interfacial shear strength, G IC, and G IIC of the CF/EP composites improved by 25, 36, and 30%, respectively, by adding 0.2 wt% nSF and 20 wt% silica nanoparticles. [ABSTRACT FROM AUTHOR]