Abstract: The invention relates to prepregs of fiber-reinforced thermosetting resin that have a coating comprising thermoplastic particles on one or both outer surfaces. Upon lamination of the prepregs into a composite, the layer comprising thermoplastic particles at the surface of the prepreg is formed into a discrete resin layer in the composite at the interface between fiber-reinforced thermosetting resin layers. The laminated composite materials have improved toughness and impact strength due to the thermoplastic particulate material at the interface and yet the composites still retain desired mechanical properties under hot/wet conditions.