Geosynthetic-reinforced soil (GRS) walls have become a good alternative in the Peruvian seismic areas due to their flexible nature and cost effectiveness over conventional retaining structures. In the practice of engineering, the analysis and design of GRS are done through limit-equilibrium methods, under static conditions, or using pseudo static methods when earthquake loads are involved. In this paper, a numerical analysis investigates the dynamic behavior of a geosynthetic reinforced soil retaining wall in Arequipa – Peru due to earthquake loading. The assumptions and methods for both the static and dynamic analysis will be fully described, from the conceptual model, choice of soil parameters and reinforcement to discussion of results. This procedure considered both the foundation soil deformability and seismic amplification of the soil. The earthquakes were generated by adjusting the history acceleration of local earthquakes to the obtained design acceleration spectrum through the seismic hazard study for a specific site. Main conclusions of the results to current pseudo-static seismic design methods and numerical analysis for reinforced soil walls turn around the failure zone, contributions of the reinforcement element and the global behavior of the structure, which are discussed in this paper.