Abstract: A pipe stabilizer is provided for maintaining pipes in a fixed relationship relative to a support structure during building construction or repair. The stabilizer is used, for example, to hold ascending pipes in place when pouring concrete slab foundations, and to stabilize piping under floors and ceilings and between adjacent wall studs. The stabilizer includes a preformed plate and at least one removable pop-out impression to accommodate pipes of varying diameter. When secured to wall, ceiling or floor structures, openings are provided in the preformed plate which permit attachment of the stabilizer to wall studs, ceiling joists and the like by tie-wires. The stabilizer may also be positioned within a form for a concrete slab on rebar studs. In an alternative form of the invention, the plate includes an extension which can be nailed to a form board and broken away from the remainder of the plate when the form board is removed.