ABSTRACT The normalized tensile reinforcement force for the seismic stability of reinforced soil walls using some rigorous methods considering the pseudo-static seismic forces is mostly used by the earlier researchers in the design of retaining walls backfilled with cohesive soil. Few studies have been presented using horizontal slice method without taking effect of the seismic acceleration in vertical direction. In the present study, a simplified solution has been presented using the pseudo-static equilibrium of the reinforced soil wall taking the effect of seismic accelerations in the horizontal and in the vertical direction. The seismic stability analysis presented here accounts the required total reinforcement strength in terms of the maximum value of reinforcement force coefficient and the critical inclination of failure plane. Taking some geometrical values of retaining wall and soil characteristics based on the literature, a detailed and comparative parametric study presented here accounts the effect of cohesion of the backfill, angle of internal friction of soil, horizontal seismic coefficient, vertical seismic coefficient and surcharge loading.