The tensile, theological, and thermal properties of dynamically vulcanized ethylene-propylene-diene terpolymer (EPDM) and linear low-density polyethylene (LLDPE) blends were reported along with their crystalline structure and morphology. The EPDM/LLDPE blends were prepared in a laboratory internal mixer by simultaneous blending and vulcanization. Vulcanization was performed with dicumyl peroxide. For comparison, linear LLDPE/EPDM blends were also prepared. In comparison to the linear blends, dynamically vulcanized blends showed higher tensile strength and modulus and exhibited improved compatibility. It was found, however, that the crystal structure of LLDPE was not changed by the inclusion of EPDM and the dynamic vulcanization process.