Vapor growth carbon nanofibers (CNFs) were used as dopants for the epoxy resin (EP) matrix of unidirectional carbon fiber reinforced plastics (CFRPs). The doped laminates were compared to the reference one (with neat EP as matrix) with regard to their fracture toughness, and mechanical quasi-static and fatigue behaviour. Electrical resistance monitoring of the samples was used as a tool for sensing the damage propagation during the various loading configurations. Correlation between these results and acoustic emission (AE) data was also attempted.