The aim of this work is to present the basics of the Smooth Particle Hydrodynamics (SPH) methode and the programme DualSPHysics. The main purpose is to find the flaws of the mentioned programme and methode in case of wave impact on the sea wall. Results have been compared with theoretical loads, calculated with Sainflou theory. Numerical results contain high frequency noise, which was filtered out using low-pass filter. After filtering out the noise, the results were very similar. Deviations between experimental and theoretical values can be explained as the consequence of negative pressure, which occures in numerical calculations.