The exceptional properties of carbon nanotubes render them potential candidates to enhance the mechanical properties of fiber reinforced composites. The current state of research suggests mixed results in terms of the enhancement that can be achieved and further research is warranted. In this research, a wide range of carbon nanotubes (CNT) volume fraction was examined between 0 and 2% on an epoxy resin carbon reinforced composite. Tensile tests were performed to measure the elastic modulus and toughness of the material. Experimental results illustrate that toughness of the material was improved by more than 100% and elastic modulus by 28% upon adding 1% CNT. Increasing the added CNT percentage by more than 1% resulted in a decrease in strength and toughness. An optimum percentage of CNT that maximizes the mechanical properties of the composite structure can be determined.