Abstract: A tool bag for use with scaffolding and ladders having rails and rungs. The bag is constructed of soft fabric. It has a front, back, sides and an open top. It is sized to fit between the rails of a ladder. The bag is fitted with vertically oriented open bottom, closed top sleeves attached to the sides of the bag. The sleeves are dimensioned to slide over the top rails of a ladder. The bag on its back has fastened on to it a pair of vertical hooks spaced to engage a rung of the ladder. The bag, in a preferred embodiment, has sleeves with horizontally positioned loose tool holding bands. The back and bottom of the bag may contain stiffening panels. Located between the hooks is an adjustable safety strap.