The effects of four surface treatments on the bonding performance of five second generation acrylic adhesives were studied. Adhesive performance was characterized using lap shear and wedge specimens exposed to elevated temperatures and humidity. For all adhesives studied, results indicated that chromic acid anodized aluminium gave superior mechanical properties as well as durability. Steel bonded adherends exhibited the best properties when grit blasting was used, while fibre glass substrates showed enhanced performance using solvent wipe. Inconclusive results were obtained with poly(methyl metha acrylate) due to its low strength compared to acrylic adhesives. Detailed analysis of the fracture surface revealed the morphology of the tougher second generation acrylics to comprise 10 mu m nitrile rubber spheres dispersed in the acrylic matrix.