An ignition switch and steering lock device for motor vehicles, comprising: a main body; an electronic control circuit provided with input/output interfaces; a locking mechanism; a mechanical actuator, for moving the locking mechanism. The locking mechanism is mobile between a locked position in which its action blocks the vehicle steering in a fixed orientation relative to the frame, and an unlocked position in which the elements do not block the rotation of the steering relative to the frame. The locking mechanism can be moved into the locked position only at a minimum steering lock orientation. The device further comprises at least one unlocked position sensor to determine the position of the locking mechanism and at least one steering orientation sensor to determine the orientation of the steering.