The aim of this work is to integrate polypropylene/montmorillonite (MMT) nanocomposite matrices into conventional fibre-reinforced composites. Two types of composite have been considered: long fibre-reinforced composites from co-woven glass fibre and nanocomposite yarns, and glass mat reinforced thermoplastic (GMT) composites. The melt spun polypropylene precursor yarns contained up to 6 wt% MMT, leading to a 2 to 3 fold increase in axial stiffness, but more modest increases were observed in extruded films and compression moulded specimens. Corresponding stiffness improvements were obtained in GMT samples. However, significantly higher temperatures and pressures were required during preimpregnation to that observed with the unmodified matrix for a given processing time.