Abstract: A ladder sack adapted for placement between the legs of a folding step ladder to provide an open platform on which to place tools or working materials while working atop the ladder, and a closed secured pouch to carry tools and working materials when the ladder is closed. The sack is formed from a rectangular section of fabric having hook and loop fasteners positioned along the sides of the sack that may be approximated to form a secured enclosure when the sack is folded end to end when the ladder is closed. When the ladder is reopened to its standing position the sack unfolds to provide easy access to the tools and working materials contained therein. The ladder sack includes straps and buckles at its ends for attachment to ladder rungs of varying sizes.