Abstract: A contoured backrest for a wheelchair may be moved to and retained in different positions and thus accommodates individuals of varying size and disabilities. The backrest carries clamps to which outriggers are fitted, and these outriggers extend transversely across the back face of the backrest. The outriggers are laterally adjustable to accommodate wheelchairs of different widths. They have offset ends beyond the sides of the backrest, and these ends fit into brackets on back posts that are part of the wheelchair. When the clamps are released, the outriggers may be rotated. This enables the position of the backrest to be adjusted forwardly and backwardly, upwardly and downwardly, and angularly.