Abstract: The invention relates to a tamper-proof hanger comprising at least one arm forming gripping jaw movably mounted in the plane of the hanger and whose mobile end may be applied against a part of the top edge of the bar supporting a garment, thus gripping a garment hanging on the hanger between the arm and the bar, and means for locking the mobile arm in closed position. This hanger is intended to prevent the theft of the garments, particularly in stores or cloakrooms.