This paper presents a comparative study of the performance of Fluid Viscous Damper (FVD) in mitigating the seismic response of both Reinforced Concrete (RC) and Steel structures. The aim of the study is to understand the behavior of the seismic resistant structures and to study the advantages of FVD over other dampers. The study is done to determine the optimum positioning of FVD in order to reduce the storey displacements and storey drifts. G+3, G+5, G+7 RC and steel structures were modeled in SAP2000 software and were subjected to non linear time history analysis under three different earthquake ground motions such as Imperial Valley – 02 (1940), Loma Prieta (1989) and Northridge-01 (1994). The dampers were placed in four different configurations such as alternate (AT), corner (CR), diagonal (DL) and middle (ML). The seismic response parameters such as the storey displacements and the storey drifts were determined for the structures. It is found that the presence of FVD reduces the storey displacement and storey drift values to about 40-70% from the uncontrolled structure. It is also understood that the optimum positioning of the dampers is greatly influenced by the aspect ratio of the building.