The seismic stability analysis of an existing earthen dam was conducted utilizing the multi-channel analysis of surface waves (MASW) system to evaluate its safety and response during earthquakes. Geophysical tests and standard penetration test (SPT) were performed at regular intervals to determine the geotechnical and dynamic properties of the dam section. The shear wave velocity for different depths within the dam section was determined through geophysical tests. Finite element modeling (FEM) by ANSYS was used to perform the static and dynamic analysis for three earthquake scenarios (EL Centro, MCE, and DBE) under different storage conditions of reservoir. From the FEM analysis, the principal stresses and corresponding horizontal displacements of the dam section were assessed. Based on the analyses, the stresses due to earthquake are much lower than strength of the dam both in compression and tension. Therefore, from the present study site specific seismic data is arrived and the dam is safe against all the earthquake scenarios considered.