Abstract: A universal mounting hook attaches to a variety of industrial and commercial adjustable shelving systems to provide interchangeability between the shelving systems. The universal mounting hook comprises a generally vertical leg and a generally horizontal leg. The vertical leg includes an "L"-shaped hook positioned at the top of the vertical leg and an abutting portion positioned at the base of the vertical leg. The abutting portion protrudes from the general line of extension of the vertical leg, in a direction opposite from the horizontal leg. The base of the abutting portion connects to an inverted "L"-shaped indentation which interconnects the vertical leg and the horizontal leg. A spring clip extends from the horizontal leg adjacent the indentation so that the spring clip and the indentation form an enclosure which receives a supporting wire. The entire mounting hook may be securely fastened to one of a plurality of different shelving systems so as to support shelving or merchandise baskets.