An experimental procedure is used to determine the transient response of an elastomeric isolator under the impact loading conditions and a numerical procedure is developed to evaluate the corresponding acceleration transmission ratio and shock response spectrum. In the experimental analysis the elastomeric isolator is connected to a resonance beam subjected to the shock loading of a pendulum striker and the shock level is measured using acceleration sensors mounted along three orthogonal directions in the basement and free end of isolator. The shock response spectrum diagram and the level of wave attenuation are determined based on the measured acceleration levels for a wide frequency range. Finite element model based on mode superposition approach is developed to analyze the impact response of elastomeric isolator using the mode shapes with frequency in range of impact excitation spectrum. Due to the importance of longitudinal response of isolators, the numerical model is employed to evaluate the longitudinal output acceleration time history of isolator. The number of elements, time step for motion equation integration and the number of mode shapes are studied and the optimized corresponding values are selected based on the convergence of the numerical results. The calculated results for wave attenuation level and shock response spectrum diagrams correlate well with the experimental measurements under two different impact loading conditions and the present model can be used to evaluate the performance of isolators depending on the level of impact loads and transmission acceleration and displacement ratios in the output of elastomeric isolators.