The aim of the present study was to demonstrate a scalable manufacturing process to graft short CNTs onto carbon fibers in order to improve the interfacial properties, whilst avoiding any loss in fiber stiffness or strength. The application of a modest potential difference during CNT synthesis has been shown to be beneficial in batch CVD conditions, improving growth uniformity and minimizing damage to the fibers during processing. The strategy for increased production was to implement this methodology in to a continuous embodiment to produce CNT-g-CFs on the tow level without laborious pre-treatment of the fiber substrate. The morphology and mechanical properties of the continuous CVD synthesized CNT-g-CFs were characterized, as was the fiber-matrix interfacial shear strength in an epoxy matrix at the single fiber level. The results are compared, in detail, to literature data for batch synthesized CNT-g-CFs.