A polypropylene (PP) composite with poly(vinyl alcohol) (PVA) fibers was produced by the direct incorporation of PVA aqueous solution into molten PP using a specific twin-screw extruder having a wide venting port. The extruded composite contained fibrous PVA dispersion with around 5 m diameter. Furthermore, the injection-molded plate exhibited high modulus and high heat distortion temperature, which are attributed to the high level of molecular orientation and the high modulus of PLA fibers.