In this study, the synergistic effect of talc content % and gamma irradiation on some mechanical, thermal, electrical resistance, and microstructural properties of the molded waste polyethylene/recycled waste rubber powder (WPE/RWRP) 60/40 was investigated. The ternary composites of talc concentrations, 5, 10, 15, and 20 wt %, were irradiated with doses of 50, 75, 100, and 150 kGy. The composites mechanical properties: tensile strength, elongation at break, and elasticity modulus, and the thermal properties: melting temperature (Tin) and (AN) were predicted. Also, scanning electron microscopy, thermogravimetric analysis, and electric conductivity were investigated. (C) 2010 Wiley Periodicals, Inc. J Appl Polym Sci 117: 2428-2435, 2010