Abstract: A lift up rail extension assembly is to be mounted onto an existing ladder which has a first rail and an opposite second rail. The first and second rails are connected by at least one step. The lift up rail extension assembly includes a first rail extension which is slidably mounted to the first rail of the existing ladder, a second rail extension which is slidably mounted to the second rail of the existing ladder, and first and second devices for latching which are pivotally mounted to the first and second rail extensions. The first and second devices for latching are movable between an unlatched position and a latched position. In addition, the first and second devices for latching each have a weighted portion so that when the respective rail extension is extended in a first direction, the weighted portion moves the devices for latching to the latched position.