Polyphenylene ether (PPE) is a polymer with very high glass transition temperature, superior thermal stability but poor melt processability. Mainly to improve its processability and chemical resistance, it is blended with Polystyrene (PS) and Nylon-6, respectively. In this research, ternary blends of PPE/PS/Nylon-6 were prepared using co-rotating twin screw extrusion and test specimens were injection molded. The influence of Maleic anhydride and screw speed on the mechanical and thermal properties of the ternary blends was investigated. The 40/40/20 blends, without Maleic anhydride, processed at screw speed of 600 min(-1) showed highest tensile, flexural and impact strengths of 65.74 MPa, 82.22 MPa and 8.88 kJ/m(2), respectively. Complete miscibility of the three polymers in the ternary blend was evidenced by scanning electron micrographs. Glass transition temperature of the ternary blend was 127 degrees C. High thermal and dimensional stability of the blend was evidenced by lowest volatile mass and highest residual mass at 800 degrees C along with decomposition temperature of 458.6 degrees C. Maleic anhydride was not effective as compatibilizer in improving the mechanical properties of the ternary blend.