Abstract: A cabinet construction system comprises a rail member mountable to a fixed support surface from which are suspended end panels by mail mounting brackets at a desired spacing. Floor and top panels are inserted between the end panels to space the end panels on the rail member to define a compartment. Connection brackets are used to secure the spacing floor and top panels to the end panels. The connection brackets are designed to quickly and efficiently lock together the component parts of the cabinets. The brackets are designed so that they are not secured by fasteners that screw directly into the panels. The brackets provide a strong and reliable interconnection of parts.