Abstract: A portable sign holding apparatus for use in single and double-hung windows generally comprising a central housing unit which includes horizontal mounting means for engaging the interior of window jambs, vertical mounting means for engaging the window sill and sash, and sign support means capable of suspending a sign in perpendicular relationship to the face of a building. In use, the horizontal and vertical mounting means engage the surfaces of windows of different sizes via telescopic adjustability to prevent lateral and vertical movement of the apparatus, respectively, within the window frame. Movement of the apparatus and support of the weight of the sign are further provided by a bracket disposed between the sign support means and the exterior wall surface of the building. In combination, the bracket, and vertical and horizontal mounting means provide a highly stable sign suspension device which may be quickly and easily installed without any screws or other invasive means.