Abstract: A ladder accessory for releasably securing a wooden extension to a leg of a ladder comprises a metal channel member for receiving the ladder extension so as to allow longitudinal sliding adjustment of the extension relative to the channel member. A shaft rotatably mounted in opposed walls of the channel member carries a plurality of gripping pins and has a handle by which the pins can be rotated into indenting engagement with the extension for gripping and retaining the extension relative to the channel member, which is secured by a clamping device to the ladder leg. The handle rests against the extension below the shaft so as to prevent rotation of the shaft by the weight of the ladder.