Anti-theft device for vehicles

Anti-theft device for vehicles, applicable to at least one of the vehicle doors for performing their locking by using a movable element (7) and preventing an unwanted opening; characterized in that it comprises a fluid pipe (1) provided with a connector (2) for the connection to a fluid circuit provided in the vehicle, and said pipe including an element (3) for increasing the fluid pressure, a first fluid on/off element (4), status of which is controlled by a first actuating control (5), and a means (6) for diving the movable element (7); so when the first actuating control (5) is first actuated, it produces the passage of fluid through the first fluid on/off element (4), the displacement of the movable element (7) and the door locking.