Abstract: A utility box for tools, parts and the like which is adapted to be placed upon and removably secured to the top platform typically provided at the top of a step ladder. The box includes a bottom wall, two side walls and two end walls forming a rectangular receptacle having approximately the same dimensions as the platform of the step ladder. A plurality of resilient retaining clips are attached to the box and are shaped to press against the lower surface of the bottom wall, the clips having sufficient resilience so that they can be opened and will press against the lower surface of the step ladder platform when the box is positioned thereon.