This document analyzes the effect of shear wall location on the seismic performance of a 5-story reinforced concrete building with a flat slab system in Erbil, Iraq. 6 models are analyzed using ETABS software: a pure flat slab model and models with shear walls placed at different exterior and interior locations. The results show that horizontal displacement, storey drift, and time period decrease with the addition of shear walls. Placement of the shear wall closer to the building center provides the best seismic performance in terms of lowest displacement, drift, and period.