This paper presents an experimental investigation on epoxy resin-carbon fibers composites interleaved with Nylon 6,6 nanofibers. In particular, the paper focuses on the effect of the thickness of the nanoreinforce into two types of laminae: unidirectional (UD) and plain wave (PW). The effectiveness of the nanoreinforce has been addressed by comparing critical and propagation energy release rates, calculated by testing samples under Mode I and Mode II fracture mechanic loads. Experiments show a general improvement in delamination resistance when the nanofibers are interleaved. Nevertheless slightly different behaviour has been found between the two types of lamina: micrographs of crack paths have been used to explain the reinforce mechanisms and such differences, suggesting a strong interaction between the nature of the fabric and the thickness of the nanointerlayer. (C) 2016 Elsevier Ltd. All rights reserved.