It is relatively easy to demonstrate analytically the high gradient of peel stresses in an adhesive layer near the overlap ends of an adhesively bonded lap joint. However, experimental validation of such a high peel stress gradient becomes quite difficult. One of the experimental methods is to measure the relative normal displacement between the two adherends bonded together by an adhesive layer and then to calculate the stresses in the adhesive layer. In this study, a simple doubler specimen was used to obtain an accurate measurement of the relative out-of-plane surface displacement using a holographic interferometry technique. Unlike a full doubler specimen, the global rotation that occurred in the overlap was removed and the effects of the end misalignment were therefore reduced. It is shown that there is a good correlation between the relative out-of-plane surface displacement measured and that predicted using finite element analysis of the misaligned specimens.