Fiber-reinforced polymer (FRP) materials have emerged as an alternative material for producing reinforcing bars for concrete structures. FRP reinforcing bars offer advantages over steel reinforcement in that FRP bars are noncorrosive, and some FRP bars are nonconductive. The professional using this technology should exercise judgment as to the appropriate application of FRP reinforcement and be aware of its limitations as discussed. Currently, areas where there is limited knowledge of the performance of FRP reinforcement include fire resistance, durability in outdoor or severe exposure conditions, bond fatigue, and bond lengths for lap splices. Further research is needed to provide additional information in these areas.