A novel numerical approach, namely Material Point Method (MPM), is applied to analyze the build-up of pore water pressure inside the landslide body during the impact against different types of structures. To this aim, the landslide soil is schematized as a two-phase elasto-plastic material, while the structural materials are assumed as one-phase elasto-plastic bodies. The complex Landslide-Structure Interaction (LSI) is simulated for different landslide scenarios, including the formation of “dead-zones” behind the structures and/or the run-up mechanisms, even including in some cases unacceptable displacements or the complete disruption of the impacted structure. Independent on site-specific conditions, it is shown that landslide pore water pressures undergo significant tempo-spatial evolution during a dynamic impact, meaning that a hydro-mechanical coupled approach is fully needed for an adequate LSI analysis.