Rheological properties of polyoxymethylene (POM) and ethylene–octene copolymer (EOC) in solid and melt states were investigated. Blends were prepared with a twin screw extruder at broad component wt-to-wt ratios (10, 30, 50, 70, 90 wt% of EOC). The morphology as well as calorimetric, rheological, and elastic properties of the blends were studied. The investigation showed that POM/EOC blends were heterogeneous in nature and had a broad phase transition region between 30 and 70 wt% of POM. Because during processing droplet breakup is enhanced for EOC-rich systems, respective blends show “better” morphology with smaller particle sizes. It was, however, observed that rheological and dynamic characteristics (such as storage E¢ and loss E² modules as well as shear elastic G¢ and viscous G² modules) were highly influenced by intrinsic incompatibility of POM and EOC. Besides, also the crystallization specifics of the investigated blends influenced their E¢ and E².