Abstract: Adjustable steps (2) extend between two parallel stingboards (3). Each stringboard (3) includes two locking flanges (4) and each step (2) is supported by four pivotable blocks (7, 8) each securable to a flange (4) by means of a nut (17). Two threaded rods (13, 16) extending through the step and between the stringboards engage two respective nuts (17) combined with two opposite blocks. The height of each step of the staircase may be adjusted by changing the spacing between the blocks (7, 8) along each flange (4). The horizontal position of the steps may be adjusted by changing the vertical distance between the front blocks (7) and rear blocks (8) along the stringboards, regardless of the angle at which the stringboards were fitted. A universal staircase may thus be achieved.