Polymer composites are currently dominated by glass fibre. Carbon and aramid fibre composites are used in high value applications. Although a few examples of steel wire reinforced polymers are found in literature, no real efforts to use steel in such applications appear to be made. Nevertheless, steel wire and steel cord offer interesting opportunities for use in polymer/steel composites. The ductility of steel filaments is a unique property that leads to better performance in impact absorbing applications where traditional fibres would simply shatter. In addition, the excellent fatigue resistance and low creep behaviour favour the use of steel reinforcement. Also, faster and simpler processing operations, currently the bottleneck for the breakthrough of thermoplastic composites, may be developed.