Abstract: The hydraulic anti-vibration device comprises: an annular rigid endpiece (1) about a vertical axis (X); a rigid stud disposed coaxially with the endpiece; a frustoconical annular wall (3) made of elastomer that withstands axial compression and that is interposed between the endpiece and the stud; a watertight flexible membrane (4); a rigid intermediate partition (5) dividing the assembly into a working chamber (A) and a compensation chamber (B); a throttled passage (6) between the chambers; and a mass of liquid (L) filling the chambers and the passage, the stud being disposed inside the working chamber and constituting the head (2.sub.1) of a suspension rod (2), and the downwardly flared annular wall (3) extending upwards inside the bottom annular portion (12) of the working chamber. At least the bottom of said bottom annular portion is provided with at least one flexible blade-like obstacle (13).