A hub-bearing unit for rotatably is provided with a stationary radially outer ring, a radially inner ring, an annular gasket, and a second metal insert. The radially inner ring includes a flange for mounting a wheel and a sealing device having a first metal insert, annular shaped, steadily fixed at an end portion of the outer ring facing the flange. The annular gasket includes a plurality of elastomeric sealing lips and steadily fixed to the metal insert. The second metal insert is steadily fixed on an axial cylindrical surface of the inner ring. The gasket presents a first axial contacting lip. The first axial contacting lip slidingly contacts a substantially frustoconical portion of the metal insert.