This study investigat the effectiveness of reduced graphene oxide as nanofiller in enhancing epoxy/carbon fiber-reinforced composite at varying temperature conditions. The graphene oxide is synthesized using modified Hummer's method and then is chemically reduced to yield reduced graphene oxide (rGO). The rGO is dispersed in epoxy matrix system through combination of mechanical and sonication methods. The flexural and shear test samples are manufactured using resin infusion technique. These samples are then tested to determine their shear and flexural properties at varying temperatures (À10 C, 23 C, 40 C) and the results correlate to neat samples. It is found that the composites' flexural strength and flexural modulus increase with rGO wt% content up to 62% and 44%, respectively. The shear testing results show improvement on the shear strength and modulus at maximum of 6% and 40%, respectively. The rGO improvements advantage is lost for flexural strength, shear strength, and modulus at elevated temperatures while flexural modulus withheld at 40% improvements over virgin epoxy/carbon fiber-reinforced composite. An interesting observation is that all samples with rGO exhibit reduced damage characteristics superior to the neat samples under flexural and shear loading conditions. This study indicates that the addition of rGO significantly alter the flexural and shear properties, failure modes, damage characteristics, and they are overall sensitive to elevated temperature conditions.