A stiffener for a printed circuit board where the stiffener is placed between the printed circuit board and a wall of the metal chassis in a computer system housing. The loaded printed circuit board may first be mounted on the stiffener, which, in turn, may then be mounted on the appropriate wall of the chassis along with the circuit board. Alternately, the stiffener may first be mounted on the appropriate chassis wall, and the circuit board may then be mounted on the stiffener. Additional circuit components may then be added onto the circuit board. The lies between the circuit board and the wall of the chassis on which the circuit board is being mounted. The back plane support provided by the stiffener may reduce damage to the conducting paths of the printed circuit board due to pressures exerted during component mounting, manufacture, transportation, etc. Additionally, a circuit board carrying densely populated electronic components may be easily mounted on or removed from the chassis without damage. Adequate board-to-chassis grounding may also be accomplished through the sheet metal stiffener frame. Horizontal and vertical struts in the stiffener frame may provide additional stiffness and rigidity in the vicinity of the high density connectors on the circuit board. Besides increased stability, unusually tight tolerances on the flatness of the circuit board surface near high density connectors may be achieved with the support provided by the stiffener.