Reinforced concrete (RC) structural walls are the primary lateral-load carrying elements in many structures designed to resist earthquakes. A review of the technical literature shows considerable uncertainty with regards to the effective stiffness of these structures when subjected to seismic excitations, which many design practices currently deal with by employing a stiffness reduction factor. In an attempt to obtain additional information regarding the stiffness of these structures, an analytical approach, combining the flexure and shear components of deformation, is proposed to evaluate the effective stiffness of the RC walls tested. Based on this proposed analytical approach, a comprehensive parametric study comprising 180 combinations was carried out and a simple equation for assessing effective stiffness of RC squat structural walls then proposed, on the basis of these parametric case studies