In Europe, wave energy developments are increasing in both number and size. Even though, most wave devices are still at the prototype development stage, an increasing number are now approaching sufficient levels of development where more advanced projects are already operative, in particular in North Europe. Accordingly, there is a growing need to consider the environmental consequences and potential impacts of these renewables activities on the marine environment. This paper presents an overview of the state of art in Europe of the existing environmental impact studies on Wave Energy Converters (hereafter WECs). A summary of the European legislation is also provided and together with an overview of the current WECs technology operating in Europe. Then, the different identified environmental impacts by technologies and life process (construction, operation and decommissioning) in the European seas is also described. This review represents a starting point to identify which are the main effects of WECs on marine and coastal environment. Possible future strategies to minimize such environmental impacts are provided. Finally, recommendations are given for future studies of Environmental Impact Assessment EIA of Marine Renewable Energy Installations MREIs in the perspective to enhance future deployments minimizing the associated impacts.