Abstract: A circuit board stiffener includes an elongated stiffening member adapted to extend over the board surface in spaced relation to that surface; the member has contact surfaces adapted to engage one side of the board, and bendable retainer structure to retain the member in position relative to the board. The retainer structure may comprise bendable arms that project through board openings to be bent at the opposite side of the board, and to be locked in position by solder at that opposite side. The member may have a zig-zag cross section to enhance its stiffness.