The present work describes the validation of an SPH-based technique forwave loading on coastal structures. The so-called DualSPHysics numerical model has been used for the scope. The attention is focused onwave impact on vertical structures and storm return walls. For vertical quay walls, the numerical results have been compared with analytical and semi-empirical solutions. Later on, the wave impact on storm return walls has beenmodelled and the results have been compared with experimental data. Regular and random waves have been simulated. Despite the model limitations (e.g. lack of an active wave absorption system), good agreement is achieved with the formulae predictions and experimental results which proves that DualSPHysics model is becoming an alternative to some classical approaches and can be used as complementary tool for the preliminary design of coastal structures.