Prepregs of carbon fibre-reinforced polymer (CFRP) composites containing carbon nanotubes (CNTs) have been successfully produced based on a solventless prepregging process. This work provides one of the most comprehensive evaluation to date of the processing and cure parameters affected by the incorporation of CNTs in CFRP prepreg manufacturing. The results confirmed that high-speed shear mixing and functionalisation of CNT are effective in lowering the viscosity of the CNT-epoxy nanocomposites. Based on the findings obtained from the rheological studies, suitable processing parameters are chosen for lab-scale production of CFRP composite prepregs. The effects of surfactant-treated CNTs on cure behaviour of epoxy and CFRP prepreg are evaluated. The catalytic activity of CNTs is negligible for a 0.5 wt% filler content whereas it becomes prominent when the CNT content is increased to 1.0 wt%. The degree of cure is lower for the prepregs containing 0.5–1.0 wt% CNTs than those without or containing a lower CNT content.