This work aims to study the behaviour against delamination under static modes I and II of adhesive bonded joints in unidirectional carbon-fibre/epoxy prepreg. The double cantilever beam and end notched flexure tests were used to characterize the influence on the interlaminar fracture toughness under pure mode I and pure mode II, respectively. Three structural adhesives from different manufacturers were tested in comparison with the original material, that is, without adhesive bonded. The fracture surfaces were also examined for each joint system.