The delamination characterization in composite laminates has conventionally involved the assessment of the strain energy release rate at critical load, al so known as fracture toughness, through double cantilever beam (DCB) experiments. This work aims to determine the mode I fracture toughness of triaxial braided composite (TBC) specimen without and with addition of Graphene nanoplatelets (GNP). The TBC specimens were produced from glass fiber braided preforms and epoxy resin and 0.5 wt% GNP using vacuum bagging technique. The Glass fiber preforms are braided at [0/±45°] braid angle on a vertical maypole braiding machine. Results indicate an increase of 27% in the mode I interlaminar fracture toughness due to the addition of GNP owing to the interaction of nanoparticles, fiber and matrix. Also, braided composites have shown better performance in terms of fracture toughness when compared to other unidirectional or woven reinforcements.