So far, very few studies have focused on the quantification of the environmental impacts of a wave energy converter. The current study presents a preliminary Life Cycle Assessment (LCA) of the MegaRoller wave energy converter, aiming to contribute to decision making regarding the least carbon- and energy-intensive design choices. The LCA encompasses all life cycle stages from “cradle-to-grave” for the wave energy converter, including the panel, foundation, PTO and mooring system, considering its deployment in Peniche, Portugal. Background data was mainly sourced from the manufacturer whereas foreground data was sourced from the Ecoinvent database (v.3.4). The resulting impact assessment of the MegaRoller is aligned with all previous studies in concluding that the main environmental impacts are due to materials use and manufacture, and mainly due to high amounts of material used, particularly steel. The scenario analysis showed that a reduction of the environmental impacts in the final design of the MegaRoller wave energy converter could potentially lie in reducing the quantity of steel by studying alternatives for its replacement. Results are generally comparable with earlier studies for ocean technologies and are very low when compared with other power generating technologies.