Abstract Even though a number of research studies have demonstrated the effectiveness of Fibre Reinforced Concrete (FRC) in improving the structural response of RC members under different loading conditions, some concerns recently arose on the sectional ductility under flexure which can be reduced under specific conditions. In fact, fibres do not significantly increase the ultimate moment of RC members and, with rather tough FRC and low strain-hardening ratio of the longitudinal rebars, the rotation capacity can substantially decrease owing to a cracking localization at ultimate limit state. This paper focuses on this topic with a number of experimental results on full-scale FRC beams tested under flexure. Experimental results evidence that fibres, when provided in sufficient amount, are able to move the beam failure from concrete crushing to steel rupture. Under certain circumstances, the overall ductility, measured in terms of displacements, may decrease. On the other hand, in all cases the addition of fibres determines a stiffer and in general enhanced post-cracking behaviour in service conditions.