Ground rubber tire (GRT) is a particulate vulcanizate consisting mainly of rubber hydrocarbon and fillers. Rubber hydrocarbon of GRT (rGRT) has been used as a partial substitute for EPDM rubber in a dynamically vulcanized EPDM/acrylic-modified HDPE (A-HDPE) blend. The blends with higher rubber content show poor processability and physical properties, while the compositions with higher plastic content behave like toughened plastics. However, the 60:40 rubber/plastic blend was found to behave as a thermoplastic elastomer, and it was observed that 50% of EPDM can be replaced by rGRT without deterioration in properties.