Abstract: The locking device of the present invention comprises a box and a lid which interlock with each other, wherein each of the box and lid has a recess therein for snugly accommodating a faucet assembly. To operate the locking device of the present invention, the box is placed upon and around a faucet assembly, the lid is aligned and interlocked with the box and then the interlocked box and lid are secured to each other by a securing device. The locking device of the present invention when mounted upon a faucet assembly and secured to itself prevents dispensing of fluids from the faucet assembly. The locking device of the present invention is preferably made of a molded, high density, glass-filled nylon plastic.