A new technique of coherent optics, speckle photography, has been applied to the study of the behavior of adhesive joints under shear stress. This technique allows the determination of the in-plane motion by a point-by-point analysis with a sensitivity of about 3 μm. This property has been used to measure the interfacial displacement of model glass-glass joints bonded by different types of adhesive when submitted to shear. The experimental results permit direct verification of Volkersen's theory as well as the determination of the actual shear modull of the thin adhesive layer. The simplicity of use and interpretation of the technique of speckle photography should lead to significant application of this method in the future for the study of adhesive joints.