A number of Wave Energy Converters (WEC) have been proposed by many researchers, but most of them are not economically competitive as a contender in the energy market. This article intends to contribute to the development of very viable concept, which called as Overtopping Breakwater for Energy Conversion (OBREC) aims to fully utilize traditional breakwaters and capturing wave energy. The OBREC and its concept have been physically modeled and tested in Aalborg University since 2012 until 2014 and showed the promising results. In present work, the most-recent CFD of FLOW 3D technology is used to provide a more reliable approach in analyzing wave flow over the structure, in particular, OBREC device. Thus, the numerical simulations are carried out for validating overtopping discharge performance from the previous experimental and prediction methods. The result shows a good agreement with the experimental data. Hence, FLOW 3D is highly capable in handling coastal issues, especially for evaluating overtopping wave parameters.