Abstract: Presented is an apparatus for stabilizing the form boards or members that define a cavity to receive wet concrete. The apparatus includes metal stakes having two sets of through-bores. The through-bores of one set are perpendicular to the through-bores of the other set and are spaced intermediately thereof. The stakes are driven into the ground in parallel pairs on opposite sides of the form boards. Nails are driven through one set of through-bores to attach the form boards to the stakes. A retention nail is slidably supported in a bore of the other set of bores so that it lies parallel to the form boards and above the top edges of the form boards. An elongated retention plate extends transversely above the form boards and opposite ends are detachably engaged to the nails that lie parallel to the form boards so as to prevent the form boards from displacing the stakes outwardly by the force exerted by the wet concrete.