Oriented poly(vinylidene fluoride) (PVDF) films with beta-form crystals have been commonly prepared by cold drawing of a melt-quenched film consisting of alpha-form crystals. In this study, we have successfully produced highly oriented PVDF thin films (20 mu m thick) with beta-crystals and a high crystallinity (55-76%), by solid-state coextrusion of a gel film to eight times the original length at an established optimum extrusion temperature of 160 degrees C, some 10 degrees C below the melting temperature. The resultant drawn films had a highly oriented (orientation function f(c) = 0.993) fibrous structure, showing high mechanical properties of an extensional elastic modulus of 8.3 GPa and tensile strength of 0.84 GPa, along the draw direction. Such highly oriented and crystalline films exhibited excellent ferroelectric and piezoelectric properties. The square hysteresis loop was significantly sharper than that of a conventional sample. The sharp switching transient yielded the remnant polarization P-r of 90 mC/m(2), and the electromechanical coupling factor k(t) was 0.24 at room temperature. These values are about 1.5 times greater than those of a conventional beta-PVDF film. Thus, solid-state coextrusion near the melting point was found to be a useful technique for the preparation of highly oriented and highly crystalline beta-PVDF films with superior mechanical and electrical properties. The morphology of the extrudate relevant to such properties is discussed.