Lightweight design, using high performance composites, which directly yields a reduced need for fuel is in the focus of new developments for traffic engineering. The increased substitution of traditional, metal based materials by fibre-reinforced composites in the aviation industry exemplifies this trend. In addition to mechanical properties, e.g. an increase in strength, that leads to direct weight savings, or improved dynamical performance, which translates into longer maintenance intervals, i.e. longer service-life. In the field of fibre-reinforced polymer matrix composites possible contributions from nanotechnology are currently reviewed. The modification of the matrix by introducing a “nanophase” has attracted most attention up-to-date. Additional approaches include modification of traditional reinforcements, as well as the development of new reinforcing materials. Desired improvements include mechanical properties, interlaminar shear strength, reinforcement in z-direction, fiber-matrix adhesion, and obtaining new functionalities. Starting from a summary of the most important effects of nano-modifiers in polymeric matrices, the presentation will review published results on the modification of thermoset matrix fiber-reinforced composites by using nanotechnology, as well as some of our own work in that field. Furthermore, applications of such modified composites in component parts are discussed.