Abstract: A security system for a metal cabinet door comprises a latch adapted to be locked by a lock operating the latching members of the door. These comprise upper and lower strip members each having a plurality of hooks each of which, when the door is closed and latched, is engaged in an opening formed in a locking profiled member attached to the cabinet and at least one rotating sector whose rotation axis is perpendicular to the plane of the door. When the door is closed and latched the sector(s) enter an opening in a longitudinal member attached to the cabinet on the same side as the hinge(s). The sector is operated in the unlatching direction by the latch through a cable and in the latching direction by a return spring.