Degradation of adhesive bonded aluminium in corrosive environment has been investigated in terms of tensile strength as a function of pre-treatment of the surface and specimen design. The pre-treatment was found to play a major role in the degradation mechanism of adhesive bonded joints. Underfilm corrosion at the substrate/adhesive interface was observed on extruded and degreased specimen, causing degradation in the tensile strength. Etching and hot AC anodising of the aluminium surface improved the adhesion and the underfilm corrosion resistance on non-ridged specimens. The results proved that specimen design can be detrimental when it comes to underfilm corrosion susceptibility of the bonded joint.