Ethylene vinyl acetate (EVA-45)/ethylene propylene diene terpolymer (EPDM) blend-layered double hydroxide (LDH) nanocomposites have been prepared by solution blending of 1:1 weight ratio of EVA and EPDM with varying amounts of organo LDH (DS-LDH). X-ray diffraction and transmission electron microscopy analysis suggest the formation of partially exfoliated EVA/EPDM/DS-LDH nanocomposites. Measurement of mechanical properties of the nanocomposites (3 wt% DSLDH content) show that the improvement in tensile strength and elongation at break are 35 and 12% higher than neat EVA/EPDM blends. Dynamic mechanical thermal analysis also shows that the storage modulus of the nanocomposites at glass transition temperature is higher compared to the pure blend. Such improvements in mechanical properties have been correlated in terms of fracture behavior of the nanocomposites using scanning electron microscopy analysis. Thermal stability of the prepared nanocomposites is substantially higher compared to neat EVA/EPDM blend, confirming the formation of high-performance polymer nanocomposites. POLYM. ENG. SCI., 49:585-591, 2009. (c) 2009 Society of Plastics Engineers