This study investigates the role played by two different interface agents on the basis of atactic polypropylene in the continuous/disperse phase polypropylene/ polyamide-6 (PP/PA6) system. The two agents used were obtained at the authors' laboratories from an atactic polypropylene byproduct derived from industrial polymerization reactors and consist of two grafted polymers containing either succinic anhydride (a-PP-SA) or both succinyl-fluorescein and succinic anhydride grafted groups (a-PP-SF/SA). The role of these grafted polymers as compatibilizers in PP/PA6 polymer blends has been confirmed in previous investigations on the basis of their macroscopic behavior. This work investigates the thermal study of these blends where polypropylene acts as the polymer matrix and polyamide as the dispersed phase. Under isothermal conditions, thermal analysis agrees with the changes in the overall system behavior caused by the presence of the interface agents. These aspects were confirmed by polarized light microscopy that showed the morphology of the blends before and after modification with a-PP-SA or a-PP-SF/SA.