Abstract: The invention pertains to a device (C) for recycling grey water, particularly for a transportation vehicle equipped with a tank (D) of clean on-board water, said device (C) being intended for providing recycled water for the emptying of at least one toilet mounted in said vehicle, said device comprising a vessel (2) for collecting grey water, a pump (4) to make at least at a part of the grey water stored in the vessel (2) circulate towards filtering means (8) and a tank (12) for storing filtered grey water useable for washing the toilets. said filtered grey water being stored under pressure in said tank (12). According to the invention, said filtering means (8) comprise an ultrafilter.