Tsunami hazard assessment of the eastern part of the Mediterranean Sea is the current interest of the countries having, a coastline in this region. Considering today's increasing population on the coasts and historical tsunamis, it is essential to estimate the probable tsunami risk, which might occur, to be able to mitigate the risk before the actual tsunami event happens. For this purpose, European Union funded project., SEAHELLARC is formed to develop a methodology and tools for seismic and tsunami safety and enhance the protection of coastal areas in the western part of Peloponnese in Greece by simultaneous observations and evaluation of onshore and offshore data. In this paper, we present the tsunami simulations of characteristics of possible tsunami source scenarios for the Pylos-Zakynthos-Filiatra and Kyparissia regions, located at western part of Greece. We use NAMIDANCE tsunami simulation and visualization tool to estimate extreme but possible tsunami wave effects in these regions. In the simulations the tsunami arrival times, maximum positive and negative amplitudes are computed, plotted, compared and discussed for the coastal areas of Zakynthos, Filiatra, Kyparissia and Pylos. Furthermore, a detailed mapping of the bathymetric features is performed to define possible landslides and lithological variations at the marine bottom. The uppermost sediments are mapped by sub-bottom profiling, while possible faults are identified by multi-channel reflection mapping at the western Peloponnese. This paper also builds upon the background of a seismic hazard assessment for the region to draw several credible tsunami occurrence scenarios that have been numerically simulated.