The toughening enhancement of Polyamide 6 blended with different types of functionalized elastomers was studied. Morphological analysis by scanning electron microscopy (SEM) were performed on undeformed samples in order to determine particle-size distribution. Yet more SEM examination of the damage zone ahead of notch tip in uniaxial tensile test provided insight into the failure mechanisms. The best impact strength was achieved with the PA6/EPDM-g-MA. (terpolymer ethylene-propylene-diene monomer grafted with Maleic Anhydride) blend, unlike ULDPE-g-MA (ultra-low-density polyethylene grafted with maleic anhydride), which possesses the poorest toughening efficiency even though opposite results would be expected from particle-size evaluation. The higher cavitation resistance of EPDM compared to ULDPE observed during low strain rate tensile test plays a crucial role in understanding the best performances of its blends.