The intensive increase of global warming every year affects our world negatively and severely. The use of renewable energy sources has gained importance in reducing and eliminating the effect of global warming. To this end, new technologies are being developed to facilitate the use of these resources. One of these technological developments is the floating wind turbine. In order to evaluate the respective environmental footprint of these systems, a life cycle assessment (LCA) is herein applied. In this study, the environmental impact of floating wind turbines is investigated using a life cycle assessment approach and the results are compared with the respective ones of onshore and jacket offshore wind turbines of the same power capacity. The studied floating wind turbine has a square foundation that is open at its centre and is connected to the seabed with a synthetic fibre-nylon anchorage system. The environmental impact of all life cycles of such a structure, i.e., the manufacture, the operation, the disposal, and the recycling stages of the wind turbines, has been evaluated. For these floating wind turbines, it has been found that the greatest environmental impact corresponds to the manufacturing stage, whilst the global warming potential and the energy payback time of a 2 MW floating wind turbine of a barge-type platform is higher than that of the onshore, the jacket offshore (2 MW) and the floating (5 MW) wind turbines on a sway floating platform.