The effects of crystallization temperature of PBS (TIC,PBS) on the fractional crystallization, phase segregation, and crystalline morphology of PEO in their miscible crystalline/crystalline blends are investigated. The crystallization kinetics and phase segregation of PEO are considerably influenced by TIC,PBS. A higher TIC,PBS results in the crystallization of PEO at an extremely large degree of supercooling and may facilitate the segregation of PEO within the interlamellar regions of PBS. At a high TIC,PBS (e.g., 95 °C), the long period, thickness of amorphous and crystalline layers of PBS increase upon blending with PEO. The TIC,PBS dependence of phase segregation of the PEO component is discussed from a thermodynamic as well as a kinetic perspective.