Aluminum high pressure die casting (HPDC) alloys are widely applied in the automotive sector. The constant needs for lightweight materials open a new opportunity for Al castings in structural applications in vehicles. New HPDC Al alloys with high ductility are available and are potential candidates for Body-in-White applications with crash requirements. Therefore, an assessment of the crashworthiness of these materials is required. In previous publications, the authors demonstrated that the fracture toughness, measured in the frame of fracture mechanics can be related to crash resistance in high strength steels and aluminum sheets. In this context, the characterization of the fracture toughness of two aluminum alloys with different ductility (AlMg4Fe2, AlMg4Fe2Zn3) was assessed following linear elastic fracture mechanics (LEFM), in terms of k icand elastic-plastic fracture mechanics (EPFM), in terms of the essential work of fracture, we. The results show that LEFM is not suitable to evaluate the fracture toughness of HPDC alloys with a significant amount of plasticity. On the other hand, it is showed that we describes the fracture toughness for high ductility alloys and it is here proposed as a material property to predict the crashworthiness of ductile HPDC alloys.