Abstract: A collapsible ladder provides a plurality of segments, each segment associated with one rung of the ladder. The segments may be folded into a flat or planar configuration, after which each segment may be folded against adjacent segments, thereby forming a stacked storage configuration. Each segment provides a generally horizontally oriented rung carried at either end by a generally vertically oriented inside element. A middle element is hinged to each inside element, and an outside element is hinged to each middle element. Side rails may be formed by folding the middle element at 90 degrees to the inside element, and the outside element at 90 degrees to the middle element. A side rail formed in this manner is generally U-shaped when viewed from the end. Springs bias the inside, middle and outside elements into a 90 degree relationship with each adjacent element.