The impact fracture toughness of several ethylene-propylene block copolymers has been evaluated using the traditional contact notch sharpening technique of tapping and a new non-contact technique based on femtolaser ablation. The fracture toughness values obtained with the specimens notched by the femtolaser ablation technique were always lower than the tapped specimens. The impact fracture toughness values of these block copolymers does not depend only on the ethylene content, but also the molecular weight has a remarkable influence. © 2014 Elsevier Ltd. All rights reserved.