Asphaltene obtained by extraction from asphalt was investigated by different analytical techniques in order to characterize its composition, molecular structure and morphology. Then, the asphaltene molecules were successfully functionalized by 3-glycidyloxypropyltrimethoxysilane and 3-aminopropyltriethoxysilane as confirmed by thermogravimetric analysis, X-ray photoelectron spectroscopy, and Fourier transform infrared spectroscopy. Finally, asphaltene/epoxy composites at four different loading levels were prepared and their thermo-mechanical properties were examined. The thermal analysis results indicated that asphaltene as a novel reinforcing filler in epoxy resin caused a significant increase in storage modulus of both glassy and rubbery regions, slightly increased the glass transition temperature without negatively affecting thermal stability, and reduced the overall cost of the material.