This paper describes a study of adhesion between elastic solids and in particular the effect of a tangential force upon the size of the contact area. In the first part of the paper, the relation between the stress intensity factor of the normally loaded contact and the overall energy balance approach is discussed. In the second and main part of the paper, an analysis is given for the influence of a tangential force on the adhesive contact. The equation derived to describe its effect on the contact size has been verified by experiments carried out on rubber hemispheres pressed against a glass flat. The experimental results show qualitatively a clear reduction in contact area when a tangential force acts and quantitatively a reasonable agreement with theory within the limits of experimental error.