New polyamide 6 (PA)/poly(amino-ether) (Blox) blends were obtained by direct injection moulding covering the full composition range. The blends comprised an almost pure PA phase and a Blox-rich phase in which significant amounts of PA were miscibilized. A very positive mechanical response was obtained, as synergisms were observed both in Young's modulus/yield stress and in elongation at break. The combined effects of the observed partial miscibility, and the very small dispersed phase size, are stated as the main factors responsible for the mechanical behaviour.