A fastener for attaching a button to a piece of fabric, the button having two or more holes, said fastener comprising a flexible filament, a first transverse bar at one end of said flexible filament, and a second transverse bar at the opposite end of said flexible filament, said first and second transverse bars being parallel to one another and perpendicular to said flexible filament, each of said first and second transverse bars having a bottom surface, said bottom surface extending downwardly furthest and having its greatest cross-sectional diameter at its midpoint and sloping upwardly and diminishing in cross-sectional diameter on opposite sides of said midpoint, said flexible filament and said pair of transverse bars being appropriately dimensioned so that said pair of transverse bars may be inserted through a corresponding pair of holes in the button and then through the piece of fabric in such a way as to be retained by the underside of the piece of fabric, with said flexible filament extending between the pair of holes.