It is well known that to better characterize the seismic phenomenon several parameters such as site effects have to be considered. Indeed, during the wave propagation process, the soil near the surface can have an effect of amplification or de-amplification on the ground motion. This may be related to soil type (soft), geology or soil heterogeneity among others. This work aims to study numerically the effect of local geology on ground motion prediction at a regional scale. The studied site is located at Kefalonia Island (Greece). This site is well characterized and instrumented by several sensors placed in such a way that allow to measure the effect of spatial variability on the recorded signals.