The fracture parameters of PC/ABS blends rich in PC were determined both at high and low strain rate. The criteria postulated by LEFM (K-IC and G(IC)) and EPFM (J(IC)) were used and compared to the plane strain Essential Work of Fracture (We) using the SENB geometry. The results showed the relationships predicted between them. The ABS shows a reinforcing effect, both at high and low strain rate, until 15 % by weight of terpolymer. The expected fracture parameter variations with the increase of the strain rate were observed until 10 % by weight of ABS. From 15 % and on, except for PC-40, there is no change, suggesting an important modification of the ductile-brittle transition and/or a lower notch’s sensitivity. The abnormal behaviour of the blend containing 40 % by weight of ABS could be attributed to the coalescent morphology obtained. The EWF concept is suggested as an alternative method or, at least, as a preliminary analysis of ductile fracture systems.