Crystallization behavior and morphology development in miscible blends of poly(vinylidene fluoride) (PVDF) and poly(vinyl acetate) (PVAc) have been investigated on the basis of light scattering, optical microscopy, and atomic force microscopy(AFM). Strikingly, a spiral crystal growth was observed at the core of the spherulites in the pure PVDF as well as in its blends with PVAc. The spiral structure appears to emerge from the aggregation of microfibrils during crystallization. The AFM study revealed that the microfibrils at the core are partially aligned with their long axes parallel to the spiral axis during the initial growth stage, but the fiber axes gradually change their orientation in the perpendicular direction as the spiral wave propagates toward an outer edge. The band periodicity was found to increase with increasing amorphous PVAc content. Furthermore, the periodic distance between neighboring spiral arms increases from the core to the outer edge, and this may be ascribed to the preferential rejection of PVAc chains into the inter-spiral regions during PVDF crystallization.