Abstract: A device for locking the wheel of a vehicle to prevent unauthorized movement of the vehicle. The device is particularly suited for use with trailers and other such vehicles that are often left at unguarded or remote locations. The device has a mounting member suitable for mounting on the underside of the vehicle frame or body and a locking member suitable for placement under one of the wheels of the vehicle. A connecting member interconnects and is hingedly connected to both the mounting and locking members. To allow use on a variety of vehicles, the connecting member is adjustable to vary its length and it adjustably connects to the mounting member. The hinged connections of the connecting member to the mounting and locking members allows the device to be placed in a collapsed configuration when it is not in use. A retaining pin is used to hold the device in the collapsed condition.