The surface of silicon dioxide (SiO2) nanoparticles was treated with oleic acid, and the resulting surface properties were characterized. Bio-based poly(lactic acid) (PLA)/poly(butylene succinate)/SiO2 nanocomposites were fabricated via solu tion blending. The influence of the SiO2 content on the thermal stability, flexural properties, impactstrength, and morphology of the prepared nanocomposites was investigated using several techniques. The impact strength of the nanocomposites with surface treated SiO2 (O-SiO2) nanoparticles substantially increased with increasing O-SiO2 content from 0 to 3wt%. Scanning electron microscopy imaging revealed that the nanocomposites with OSiO2 nanoparticles exhibited numerous tortuous cracks and ridges, indicating ductile deformation prior to fracturing.