In the first paper of this series, we reported the direct influence of interfacial adhesion on the impact strength of PVC–NBR blends with the morphology of well-dispersed rubber particles [2]. In the present work, we use the same PVC–NBR blends with two different levels of interfacial adhesion to investigate the direct effect of interfacial adhesion on the toughness of the blends determined by the lowspeed tensile measurements. Microvoiding mechanisms, such as crazing [1], internal cavitation of rubber particles [6,11] and debonding between the matrix and dispersed particles [2,12–14], relieve the triaxial dilatational stresses ahead a crack tip, thereby promoting plastic deformation. Therefore, microvoiding is one of the most important toughening mechanisms. In this paper, the role of microvoiding in the toughening of the PVC– NBR blends is also discussed.