Abstract: The Big-Un™ vehicle security device prevents the theft of vehicles and is particularly suitable for use with large vehicles such as commercial vehicles, emergency vehicles, heavy plant, military vehicles and utility vehicles. In use, the device prevents at least one pedal being operated comprising: a security device and a locking member which is releaseably connected to the securing device and which prevents the or each pedal being operated wherein said securing device comprises an elongated member sized such that it extends from the or each pedal through an aperture in the steering wheel and into the area normally occupied by a driver when seated within the vehicle in the conventional driving position.