The influence of hyperbranched polymer grafted polypropylene (PP-HBP) on the morphology of polypropylene (PP)/polyamide 6 (PA6) blends has been investigated. The final morphology was strongly influenced by the PP-HBP compatibilizer concentration. At low concentrations, PP-HBP acts as an emulsifying agent, reducing the size of the dispersed phase and preventing coalescence. This is due to the high reactivity and diffusitivity of PP-HBP rapidly forming a high density of copolymers at the interface. Compared to the use of maleic anhydride grafted PP (PP-MAH) at identical concentrations, PP-HBP yielded a smaller dispersed phase particle size. Therefore, PP-HBP allows the use of less compatibilizer to obtain identical morphologies. At higher compatibilizer concentrations, it has been shown that the PP-HBP efficiently stabilizes the interface and inhibits both coalescence and breakup of the PAS droplets. The high concentration of reactive sites and the ability of PP-HBP to react with both chain-ends of PAS suggest that interfacial stabilization occurs because of the formation of a partly crosslinked interface. The interfacial stabilization effects generated by PP-HBP should allow one to control the morphology of polymer blends in order to create specific functional morphologies.