Polymer electrolyte membrane fuel cells (PEMFCs) have the potential to play a major role as energy sources for transportation and portable applications because it features a high power density at a relatively low operating temperature. Bipolar plates are accounts for a great part in weight, volume, and cost of PEMFC. Generally, bipolar plates need high electrical conductivity, flexural strength, gas tightness, and chemical stability. Among various materials, carbon fiber reinforced thermoplastic composite bipolar plates have been attracted by the researchers owing to its excellent corrosion resistance, high flexibility, and easy fabrication process. But the molten viscosity of thermoplastic resins is extremely high, which makes it difficult to impregnate thermoplastic resin into fiber bundles. In this study, a bipolar plate for PEMFCs was fabricated by using carbon fiber/polypropylene (PP) composites. Carbon fiber/PP prepregs were prepared by using PP sol impregnation method to improve the degree of impregnation. The interfacial contact resistance was measured with respect to the surface treatment of the composite bipolar plates. The total resistance, flexural strength, and gas permeability were investigated by using four point prove method, three point bending test, and unsteady-state permeability measurement method. Moreover, unit cell performance assessment was conducted with the thermoplastic composite bipolar plates and the results were compared with the commercial bipolar plate.