An anti-theft device for a motor vehicle with a steering wheel and a driver's seat, comprising a first rod disposed on one side of the rim and a spoke of the steering wheel, a projector bar extending toward the driver's seat, a second rod being disposed on the other side of the rim and the spoke of the steering wheel, a locking spike attached to the second rod, and means for locking the projector bar and the locking spike to the first rod for clamping opposite sides of the steering wheel and preventing a person from sitting on the driver's seat.