A retractable access device (1) adapted to be moved between a first contracted configuration and a second expanded configuration. The access device (1) includes a landing (2), at least one tread step (3), and a pair of linkage assemblies (4). Each linkage assembly (4) is pivotally attached to a respective side edge of each step (3), and includes a plurality of pivotally connected links to support and effect upward and downward movement of each tread step (3) relative to said landing (2).