Abstract: A toolbox for use with a foldable stepladder has a housing and a top plate with a peripheral lip extending above the top plate for retaining objects placed on the top plate. The housing may have one enclosure or, a different embodiment, a pair of housing portions secured on opposite sides of the top plate. When the toolbox has two housing portions a central plate defining the top plate rests on a top step of a ladder. In the embodiment using one enclosure, the toolbox is hooked to an underside of an upper step and is positioned in a cantilevered fashion below the top step.