The polymer blends offer end products with better thermo-mechanical properties and they can be more economical. Hence, the interest in the blends by the plastics industry has been increasing and the industry has been moving towards more complex systems. In the present work, an attempt was made to improve compatibility in a polymer blend composed of two normally incompatible constituents, namely, low density polyethylene (LDPE) and polystyrene (PS), through the addition of a compatibilizer. The compatibilizing agent, styrene–ethylenebutadiene– styrene block copolymer (SEBS), was added to the polymer blend in ratios of 5, 10, 20, and 30 wt% with a twin-screw extruder. The morphology and the compatibility of the mixtures were examined by scanning electron microscopy. Further, all blends of LDPE/PS/SEBS were tested to examination to obtain their tribological properties. The result showed that the addition of SEBS to the PS/LDPE blend increased the friction coefficient and the wear rate.