AbstractAn investigation according to LEFM (Linear Elastic Fracture Mechanics) principles has been carried out to determine impact resistance of PP (polypropylene) containing calcium carbonate in comparison with other types of mineral fillers. The tests have also allowed us to emphasize the strong influence of matrix brittleness or ductility on decreasing or increasing of toughness. In any case, of those materials tested, the calcium‐carbonate‐filled polypropylene is the material with the best performance. Scanning microscope (SEM) analysis and comparison of the results with the theoretical models reported in the literature made it possible to point out some particular aspects of this type of behav