Transition from unoriented &ggr; to oriented &bgr; phases is followed during stretching poly(vinylidene fluoride) at 150 °C, using both x‐ray and small angle light scattering techniques. It is observed that the &ggr;→&bgr; transition occurs simultaneously with the morphologic transition from spherulitic to fibrillar state. The threshold draw ratio is &lgr;?2, corresponding to a chain orientation functionfH?0.5; the conversion into &bgr; phase is complete at draw ratios &lgr;?4.