The effect of spandrel walls on the stiffness and ultimate strength of reinforced concrete columns was studied. Twenty-six columns are subjected to cyclic loading with deflection-control. The effect of connecting position of the walls can be neglected to estimate the yield stiffness and ultimate strength of reinforced concrete columns. The strength, however, is influenced by the thickness and height of spandrel walls. The effective height of column with spandrel walls by the AIJ Code is found to be conservative. The more effective equations to estimate the stiffness and ultimate strength for the columns with spandrel walls are proposed herein.