Vacuum infusion process was employed for the fabrication of carbon fiber reinforced polymeric (CFRP) composites modified by graphene. Three different methods were utilized for the incorporation of graphene into the CFRP composites. In the first and second approaches, graphene sheets were respectively electrosprayed on the surface of carbon fibers as interface modifiers and dispersed into the epoxy resin to improve the matrix properties. The third method includes the concurrent usage of both treatments just mentioned above. The viscoelastic behavior of composites was examined by dynamical mechanical testing at different temperatures, frequencies and graphene integration configurations. In addition, the effect of graphene on the electrical conductivity, thermal diffusivity and electro-thermal performance of composites was also studied in detail. The results indicated that the fiber reinforced polymeric composites gain multi-functionality while preserving their mechanical integrity for all graphene integration configurations with significant improvements when graphene is used simultaneously as the interface modifier and the matrix reinforcement.